diff --git a/dlls/msvcrt/data.c b/dlls/msvcrt/data.c
index 2f9f521d1ac..8b6c34abf56 100644
--- a/dlls/msvcrt/data.c
+++ b/dlls/msvcrt/data.c
@@ -18,6 +18,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
+#include <fcntl.h>
 #include <math.h>
 #include "msvcrt.h"
 #include <winnls.h>
@@ -276,7 +277,7 @@ int* CDECL __p__fmode(void) { return &MSVCRT__fmode; }
 int CDECL _set_fmode(int mode)
 {
     /* TODO: support _O_WTEXT */
-    if(!MSVCRT_CHECK_PMT(mode==MSVCRT__O_TEXT || mode==MSVCRT__O_BINARY))
+    if(!MSVCRT_CHECK_PMT(mode==_O_TEXT || mode==_O_BINARY))
         return EINVAL;
 
     MSVCRT__fmode = mode;
@@ -435,7 +436,7 @@ void msvcrt_init_args(void)
   MSVCRT__HUGE = HUGE_VAL;
   MSVCRT___setlc_active = 0;
   MSVCRT___unguarded_readlc_active = 0;
-  MSVCRT__fmode = MSVCRT__O_TEXT;
+  MSVCRT__fmode = _O_TEXT;
 
   MSVCRT__environ = msvcrt_SnapshotOfEnvironmentA(NULL);
   MSVCRT___initenv = msvcrt_SnapshotOfEnvironmentA(NULL);
diff --git a/dlls/msvcrt/exit.c b/dlls/msvcrt/exit.c
index bb977f7c957..492bcbf7b21 100644
--- a/dlls/msvcrt/exit.c
+++ b/dlls/msvcrt/exit.c
@@ -50,8 +50,8 @@ static CRITICAL_SECTION MSVCRT_onexit_cs = { &MSVCRT_onexit_cs_debug, -1, 0, 0,
 extern int MSVCRT_app_type;
 extern wchar_t *MSVCRT__wpgmptr;
 
-static unsigned int MSVCRT_abort_behavior =  MSVCRT__WRITE_ABORT_MSG | MSVCRT__CALL_REPORTFAULT;
-static int MSVCRT_error_mode = MSVCRT__OUT_TO_DEFAULT;
+static unsigned int MSVCRT_abort_behavior =  _WRITE_ABORT_MSG | _CALL_REPORTFAULT;
+static int MSVCRT_error_mode = _OUT_TO_DEFAULT;
 
 void (*CDECL _aexit_rtn)(int) = _exit;
 
@@ -230,8 +230,8 @@ void CDECL _amsg_exit(int errnum)
 {
   TRACE("(%d)\n", errnum);
 
-  if ((MSVCRT_error_mode == MSVCRT__OUT_TO_MSGBOX) ||
-     ((MSVCRT_error_mode == MSVCRT__OUT_TO_DEFAULT) && (MSVCRT_app_type == 2)))
+  if ((MSVCRT_error_mode == _OUT_TO_MSGBOX) ||
+     ((MSVCRT_error_mode == _OUT_TO_DEFAULT) && (MSVCRT_app_type == 2)))
   {
     char text[32];
     sprintf(text, "Error: R60%d",errnum);
@@ -249,10 +249,10 @@ void CDECL abort(void)
 {
   TRACE("()\n");
 
-  if (MSVCRT_abort_behavior & MSVCRT__WRITE_ABORT_MSG)
+  if (MSVCRT_abort_behavior & _WRITE_ABORT_MSG)
   {
-    if ((MSVCRT_error_mode == MSVCRT__OUT_TO_MSGBOX) ||
-       ((MSVCRT_error_mode == MSVCRT__OUT_TO_DEFAULT) && (MSVCRT_app_type == 2)))
+    if ((MSVCRT_error_mode == _OUT_TO_MSGBOX) ||
+       ((MSVCRT_error_mode == _OUT_TO_DEFAULT) && (MSVCRT_app_type == 2)))
     {
       DoMessageBox("Runtime error!", "abnormal program termination");
     }
@@ -273,7 +273,7 @@ unsigned int CDECL _set_abort_behavior(unsigned int flags, unsigned int mask)
   unsigned int old = MSVCRT_abort_behavior;
 
   TRACE("%x, %x\n", flags, mask);
-  if (mask & MSVCRT__CALL_REPORTFAULT)
+  if (mask & _CALL_REPORTFAULT)
     FIXME("_WRITE_CALL_REPORTFAULT unhandled\n");
 
   MSVCRT_abort_behavior = (MSVCRT_abort_behavior & ~mask) | (flags & mask);
@@ -288,8 +288,8 @@ void CDECL _wassert(const wchar_t* str, const wchar_t* file, unsigned int line)
 {
   TRACE("(%s,%s,%d)\n", debugstr_w(str), debugstr_w(file), line);
 
-  if ((MSVCRT_error_mode == MSVCRT__OUT_TO_MSGBOX) ||
-     ((MSVCRT_error_mode == MSVCRT__OUT_TO_DEFAULT) && (MSVCRT_app_type == 2)))
+  if ((MSVCRT_error_mode == _OUT_TO_MSGBOX) ||
+     ((MSVCRT_error_mode == _OUT_TO_DEFAULT) && (MSVCRT_app_type == 2)))
   {
     wchar_t text[2048];
     _snwprintf(text, sizeof(text), L"File: %ls\nLine: %d\n\nExpression: \"%ls\"", file, line, str);
@@ -510,7 +510,7 @@ int CDECL _set_error_mode(int mode)
 {
 
   const int old = MSVCRT_error_mode;
-  if ( MSVCRT__REPORT_ERRMODE != mode ) {
+  if ( _REPORT_ERRMODE != mode ) {
     MSVCRT_error_mode = mode;
   }
   return old;
diff --git a/dlls/msvcrt/file.c b/dlls/msvcrt/file.c
index 21ef0e82408..ba534568119 100644
--- a/dlls/msvcrt/file.c
+++ b/dlls/msvcrt/file.c
@@ -27,8 +27,11 @@
  */
 
 #include <direct.h>
+#include <fcntl.h>
 #include <io.h>
+#include <share.h>
 #include <stdarg.h>
+#include <sys/locking.h>
 #include <sys/types.h>
 #include <sys/utime.h>
 #include <time.h>
@@ -66,9 +69,9 @@ WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
 #undef _wstat64
 
 /* for stat mode, permissions apply to all,owner and group */
-#define ALL_S_IREAD  (MSVCRT__S_IREAD  | (MSVCRT__S_IREAD  >> 3) | (MSVCRT__S_IREAD  >> 6))
-#define ALL_S_IWRITE (MSVCRT__S_IWRITE | (MSVCRT__S_IWRITE >> 3) | (MSVCRT__S_IWRITE >> 6))
-#define ALL_S_IEXEC  (MSVCRT__S_IEXEC  | (MSVCRT__S_IEXEC  >> 3) | (MSVCRT__S_IEXEC  >> 6))
+#define ALL_S_IREAD  (_S_IREAD  | (_S_IREAD  >> 3) | (_S_IREAD  >> 6))
+#define ALL_S_IWRITE (_S_IWRITE | (_S_IWRITE >> 3) | (_S_IWRITE >> 6))
+#define ALL_S_IEXEC  (_S_IEXEC  | (_S_IEXEC  >> 3) | (_S_IEXEC  >> 6))
 
 /* _access() bit flags FIXME: incomplete */
 #define MSVCRT_W_OK      0x02
@@ -894,7 +897,7 @@ int CDECL _chmod(const char *path, int flags)
 
   if (oldFlags != INVALID_FILE_ATTRIBUTES)
   {
-    DWORD newFlags = (flags & MSVCRT__S_IWRITE)? oldFlags & ~FILE_ATTRIBUTE_READONLY:
+    DWORD newFlags = (flags & _S_IWRITE)? oldFlags & ~FILE_ATTRIBUTE_READONLY:
       oldFlags | FILE_ATTRIBUTE_READONLY;
 
     if (newFlags == oldFlags || SetFileAttributesA(path, newFlags))
@@ -913,7 +916,7 @@ int CDECL _wchmod(const wchar_t *path, int flags)
 
   if (oldFlags != INVALID_FILE_ATTRIBUTES)
   {
-    DWORD newFlags = (flags & MSVCRT__S_IWRITE)? oldFlags & ~FILE_ATTRIBUTE_READONLY:
+    DWORD newFlags = (flags & _S_IWRITE)? oldFlags & ~FILE_ATTRIBUTE_READONLY:
       oldFlags | FILE_ATTRIBUTE_READONLY;
 
     if (newFlags == oldFlags || SetFileAttributesW(path, newFlags))
@@ -1127,7 +1130,7 @@ int CDECL _dup2(int od, int nd)
     if (DuplicateHandle(GetCurrentProcess(), info_od->handle,
      GetCurrentProcess(), &handle, 0, TRUE, DUPLICATE_SAME_ACCESS))
     {
-      int wxflag = info_od->wxflag & ~MSVCRT__O_NOINHERIT;
+      int wxflag = info_od->wxflag & ~_O_NOINHERIT;
 
       if (info_nd->wxflag & WX_OPEN)
         _close(nd);
@@ -1370,11 +1373,11 @@ int CDECL _locking(int fd, int mode, __msvcrt_long nbytes)
   }
 
   TRACE(":fd (%d) by 0x%08Ix mode %s\n",
-        fd,nbytes,(mode==MSVCRT__LK_UNLCK)?"_LK_UNLCK":
-        (mode==MSVCRT__LK_LOCK)?"_LK_LOCK":
-        (mode==MSVCRT__LK_NBLCK)?"_LK_NBLCK":
-        (mode==MSVCRT__LK_RLCK)?"_LK_RLCK":
-        (mode==MSVCRT__LK_NBRLCK)?"_LK_NBRLCK":
+        fd,nbytes,(mode==_LK_UNLCK)?"_LK_UNLCK":
+        (mode==_LK_LOCK)?"_LK_LOCK":
+        (mode==_LK_NBLCK)?"_LK_NBLCK":
+        (mode==_LK_RLCK)?"_LK_RLCK":
+        (mode==_LK_NBRLCK)?"_LK_NBRLCK":
                           "UNKNOWN");
 
   if ((cur_locn = SetFilePointer(info->handle, 0L, NULL, FILE_CURRENT)) == INVALID_SET_FILE_POINTER)
@@ -1384,7 +1387,7 @@ int CDECL _locking(int fd, int mode, __msvcrt_long nbytes)
     *_errno() = EINVAL; /* FIXME */
     return -1;
   }
-  if (mode == MSVCRT__LK_LOCK || mode == MSVCRT__LK_RLCK)
+  if (mode == _LK_LOCK || mode == _LK_RLCK)
   {
     int nretry = 10;
     ret = 1; /* just to satisfy gcc */
@@ -1395,7 +1398,7 @@ int CDECL _locking(int fd, int mode, __msvcrt_long nbytes)
       Sleep(1);
     }
   }
-  else if (mode == MSVCRT__LK_UNLCK)
+  else if (mode == _LK_UNLCK)
     ret = UnlockFile(info->handle, cur_locn, 0L, nbytes, 0L);
   else
     ret = LockFile(info->handle, cur_locn, 0L, nbytes, 0L);
@@ -1556,15 +1559,15 @@ static int msvcrt_get_flags(const wchar_t* mode, int *open_flags, int* stream_fl
   switch(*mode++)
   {
   case 'R': case 'r':
-    *open_flags = plus ? MSVCRT__O_RDWR : MSVCRT__O_RDONLY;
+    *open_flags = plus ? _O_RDWR : _O_RDONLY;
     *stream_flags = plus ? _IORW : _IOREAD;
     break;
   case 'W': case 'w':
-    *open_flags = MSVCRT__O_CREAT | MSVCRT__O_TRUNC | (plus  ? MSVCRT__O_RDWR : MSVCRT__O_WRONLY);
+    *open_flags = _O_CREAT | _O_TRUNC | (plus  ? _O_RDWR : _O_WRONLY);
     *stream_flags = plus ? _IORW : _IOWRT;
     break;
   case 'A': case 'a':
-    *open_flags = MSVCRT__O_CREAT | MSVCRT__O_APPEND | (plus  ? MSVCRT__O_RDWR : MSVCRT__O_WRONLY);
+    *open_flags = _O_CREAT | _O_APPEND | (plus  ? _O_RDWR : _O_WRONLY);
     *stream_flags = plus ? _IORW : _IOWRT;
     break;
   default:
@@ -1578,18 +1581,18 @@ static int msvcrt_get_flags(const wchar_t* mode, int *open_flags, int* stream_fl
     switch (*mode++)
     {
     case 'B': case 'b':
-      *open_flags |=  MSVCRT__O_BINARY;
-      *open_flags &= ~MSVCRT__O_TEXT;
+      *open_flags |=  _O_BINARY;
+      *open_flags &= ~_O_TEXT;
       break;
     case 't':
-      *open_flags |=  MSVCRT__O_TEXT;
-      *open_flags &= ~MSVCRT__O_BINARY;
+      *open_flags |=  _O_TEXT;
+      *open_flags &= ~_O_BINARY;
       break;
     case 'D':
-      *open_flags |= MSVCRT__O_TEMPORARY;
+      *open_flags |= _O_TEMPORARY;
       break;
     case 'T':
-      *open_flags |= MSVCRT__O_SHORT_LIVED;
+      *open_flags |= _O_SHORT_LIVED;
       break;
     case 'c':
       *stream_flags |= MSVCRT__IOCOMMIT;
@@ -1598,7 +1601,7 @@ static int msvcrt_get_flags(const wchar_t* mode, int *open_flags, int* stream_fl
       *stream_flags &= ~MSVCRT__IOCOMMIT;
       break;
     case 'N':
-      *open_flags |= MSVCRT__O_NOINHERIT;
+      *open_flags |= _O_NOINHERIT;
       break;
     case '+':
     case ' ':
@@ -1629,17 +1632,17 @@ static int msvcrt_get_flags(const wchar_t* mode, int *open_flags, int* stream_fl
 
     if(!_wcsnicmp(L"utf-8", mode, 5))
     {
-      *open_flags |= MSVCRT__O_U8TEXT;
+      *open_flags |= _O_U8TEXT;
       mode += 5;
     }
     else if(!_wcsnicmp(L"utf-16le", mode, 8))
     {
-      *open_flags |= MSVCRT__O_U16TEXT;
+      *open_flags |= _O_U16TEXT;
       mode += 8;
     }
     else if(!_wcsnicmp(L"unicode", mode, 7))
     {
-      *open_flags |= MSVCRT__O_WTEXT;
+      *open_flags |= _O_WTEXT;
       mode += 7;
     }
     else
@@ -1774,13 +1777,13 @@ int CDECL _fstat64(int fd, struct _stat64* buf)
   if (type == FILE_TYPE_PIPE)
   {
     buf->st_dev = buf->st_rdev = fd;
-    buf->st_mode = MSVCRT__S_IFIFO;
+    buf->st_mode = _S_IFIFO;
     buf->st_nlink = 1;
   }
   else if (type == FILE_TYPE_CHAR)
   {
     buf->st_dev = buf->st_rdev = fd;
-    buf->st_mode = MSVCRT__S_IFCHR;
+    buf->st_mode = _S_IFCHR;
     buf->st_nlink = 1;
   }
   else /* FILE_TYPE_DISK etc. */
@@ -1792,7 +1795,7 @@ int CDECL _fstat64(int fd, struct _stat64* buf)
       release_ioinfo(info);
       return -1;
     }
-    buf->st_mode = MSVCRT__S_IFREG | 0444;
+    buf->st_mode = _S_IFREG | 0444;
     if (!(hfi.dwFileAttributes & FILE_ATTRIBUTE_READONLY))
       buf->st_mode |= 0222;
     buf->st_size  = ((__int64)hfi.nFileSizeHigh << 32) + hfi.nFileSizeLow;
@@ -2090,28 +2093,23 @@ static unsigned split_oflags(unsigned oflags)
     int wxflags = 0;
     unsigned unsupp; /* until we support everything */
 
-    if (oflags & MSVCRT__O_APPEND)              wxflags |= WX_APPEND;
-    if (oflags & MSVCRT__O_BINARY)              {/* Nothing to do */}
-    else if (oflags & MSVCRT__O_TEXT)           wxflags |= WX_TEXT;
-    else if (oflags & MSVCRT__O_WTEXT)          wxflags |= WX_TEXT;
-    else if (oflags & MSVCRT__O_U16TEXT)        wxflags |= WX_TEXT;
-    else if (oflags & MSVCRT__O_U8TEXT)         wxflags |= WX_TEXT;
+    if (oflags & _O_APPEND)              wxflags |= WX_APPEND;
+    if (oflags & _O_BINARY)              {/* Nothing to do */}
+    else if (oflags & _O_TEXT)           wxflags |= WX_TEXT;
+    else if (oflags & _O_WTEXT)          wxflags |= WX_TEXT;
+    else if (oflags & _O_U16TEXT)        wxflags |= WX_TEXT;
+    else if (oflags & _O_U8TEXT)         wxflags |= WX_TEXT;
     else
     {
         int fmode;
         _get_fmode(&fmode);
-        if (!(fmode & MSVCRT__O_BINARY))        wxflags |= WX_TEXT; /* default to TEXT*/
+        if (!(fmode & _O_BINARY))        wxflags |= WX_TEXT; /* default to TEXT*/
     }
-    if (oflags & MSVCRT__O_NOINHERIT)           wxflags |= WX_DONTINHERIT;
+    if (oflags & _O_NOINHERIT)           wxflags |= WX_DONTINHERIT;
 
-    if ((unsupp = oflags & ~(
-                    MSVCRT__O_BINARY|MSVCRT__O_TEXT|MSVCRT__O_APPEND|
-                    MSVCRT__O_TRUNC|MSVCRT__O_EXCL|MSVCRT__O_CREAT|
-                    MSVCRT__O_RDWR|MSVCRT__O_WRONLY|MSVCRT__O_TEMPORARY|
-                    MSVCRT__O_NOINHERIT|
-                    MSVCRT__O_SEQUENTIAL|MSVCRT__O_RANDOM|MSVCRT__O_SHORT_LIVED|
-                    MSVCRT__O_WTEXT|MSVCRT__O_U16TEXT|MSVCRT__O_U8TEXT
-                    )))
+    if ((unsupp = oflags & ~(_O_BINARY | _O_TEXT | _O_APPEND | _O_TRUNC | _O_EXCL | _O_CREAT |
+                    _O_RDWR | _O_WRONLY | _O_TEMPORARY | _O_NOINHERIT | _O_SEQUENTIAL |
+                    _O_RANDOM | _O_SHORT_LIVED | _O_WTEXT | _O_U16TEXT | _O_U8TEXT)))
         ERR(":unsupported oflags 0x%04x\n",unsupp);
 
     return wxflags;
@@ -2133,7 +2131,7 @@ int CDECL _pipe(int *pfds, unsigned int psize, int textmode)
   }
 
   sa.nLength = sizeof(SECURITY_ATTRIBUTES);
-  sa.bInheritHandle = !(textmode & MSVCRT__O_NOINHERIT);
+  sa.bInheritHandle = !(textmode & _O_NOINHERIT);
   sa.lpSecurityDescriptor = NULL;
   if (CreatePipe(&readHandle, &writeHandle, &sa, psize))
   {
@@ -2179,11 +2177,11 @@ static int check_bom(HANDLE h, int oflags, BOOL seek)
         return oflags;
 
     if (r==sizeof(utf8_bom) && !memcmp(bom, utf8_bom, sizeof(utf8_bom))) {
-        oflags = (oflags & ~(MSVCRT__O_WTEXT | MSVCRT__O_U16TEXT)) | MSVCRT__O_U8TEXT;
+        oflags = (oflags & ~(_O_WTEXT | _O_U16TEXT)) | _O_U8TEXT;
     }else if (r>=sizeof(utf16_bom) && !memcmp(bom, utf16_bom, sizeof(utf16_bom))) {
         if (seek && r>2)
             SetFilePointer(h, 2, NULL, FILE_BEGIN);
-        oflags = (oflags & ~(MSVCRT__O_WTEXT | MSVCRT__O_U8TEXT)) | MSVCRT__O_U16TEXT;
+        oflags = (oflags & ~(_O_WTEXT | _O_U8TEXT)) | _O_U16TEXT;
     }else if (seek) {
         SetFilePointer(h, 0, NULL, FILE_BEGIN);
     }
@@ -2210,28 +2208,28 @@ int CDECL _wsopen_dispatch( const wchar_t* path, int oflags, int shflags, int pm
 
   *fd = -1;
   wxflag = split_oflags(oflags);
-  switch (oflags & (MSVCRT__O_RDONLY | MSVCRT__O_WRONLY | MSVCRT__O_RDWR))
+  switch (oflags & (_O_RDONLY | _O_WRONLY | _O_RDWR))
   {
-  case MSVCRT__O_RDONLY: access |= GENERIC_READ; break;
-  case MSVCRT__O_WRONLY: access |= GENERIC_WRITE; break;
-  case MSVCRT__O_RDWR:   access |= GENERIC_WRITE | GENERIC_READ; break;
+  case _O_RDONLY: access |= GENERIC_READ; break;
+  case _O_WRONLY: access |= GENERIC_WRITE; break;
+  case _O_RDWR:   access |= GENERIC_WRITE | GENERIC_READ; break;
   }
 
-  if (oflags & MSVCRT__O_CREAT)
+  if (oflags & _O_CREAT)
   {
-    if (secure && !MSVCRT_CHECK_PMT(!(pmode & ~(MSVCRT__S_IREAD | MSVCRT__S_IWRITE))))
+    if (secure && !MSVCRT_CHECK_PMT(!(pmode & ~(_S_IREAD | _S_IWRITE))))
       return EINVAL;
 
-    if (oflags & MSVCRT__O_EXCL)
+    if (oflags & _O_EXCL)
       creation = CREATE_NEW;
-    else if (oflags & MSVCRT__O_TRUNC)
+    else if (oflags & _O_TRUNC)
       creation = CREATE_ALWAYS;
     else
       creation = OPEN_ALWAYS;
   }
-  else  /* no MSVCRT__O_CREAT */
+  else  /* no _O_CREAT */
   {
-    if (oflags & MSVCRT__O_TRUNC)
+    if (oflags & _O_TRUNC)
       creation = TRUNCATE_EXISTING;
     else
       creation = OPEN_EXISTING;
@@ -2239,16 +2237,16 @@ int CDECL _wsopen_dispatch( const wchar_t* path, int oflags, int shflags, int pm
 
   switch( shflags )
   {
-    case MSVCRT__SH_DENYRW:
+    case _SH_DENYRW:
       sharing = 0L;
       break;
-    case MSVCRT__SH_DENYWR:
+    case _SH_DENYWR:
       sharing = FILE_SHARE_READ;
       break;
-    case MSVCRT__SH_DENYRD:
+    case _SH_DENYRD:
       sharing = FILE_SHARE_WRITE;
       break;
-    case MSVCRT__SH_DENYNO:
+    case _SH_DENYNO:
       sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
       break;
     default:
@@ -2256,12 +2254,12 @@ int CDECL _wsopen_dispatch( const wchar_t* path, int oflags, int shflags, int pm
       return EINVAL;
   }
 
-  if (!(pmode & ~MSVCRT_umask & MSVCRT__S_IWRITE))
+  if (!(pmode & ~MSVCRT_umask & _S_IWRITE))
       attrib = FILE_ATTRIBUTE_READONLY;
   else
       attrib = FILE_ATTRIBUTE_NORMAL;
 
-  if (oflags & MSVCRT__O_TEMPORARY)
+  if (oflags & _O_TEMPORARY)
   {
       attrib |= FILE_FLAG_DELETE_ON_CLOSE;
       access |= DELETE;
@@ -2270,9 +2268,9 @@ int CDECL _wsopen_dispatch( const wchar_t* path, int oflags, int shflags, int pm
 
   sa.nLength              = sizeof( SECURITY_ATTRIBUTES );
   sa.lpSecurityDescriptor = NULL;
-  sa.bInheritHandle       = !(oflags & MSVCRT__O_NOINHERIT);
+  sa.bInheritHandle       = !(oflags & _O_NOINHERIT);
 
-  if ((oflags&(MSVCRT__O_WTEXT|MSVCRT__O_U16TEXT|MSVCRT__O_U8TEXT))
+  if ((oflags & (_O_WTEXT | _O_U16TEXT | _O_U8TEXT))
           && (creation==OPEN_ALWAYS || creation==OPEN_EXISTING)
           && !(access&GENERIC_READ))
   {
@@ -2292,7 +2290,7 @@ int CDECL _wsopen_dispatch( const wchar_t* path, int oflags, int shflags, int pm
     return *_errno();
   }
 
-  if (oflags & (MSVCRT__O_WTEXT|MSVCRT__O_U16TEXT|MSVCRT__O_U8TEXT))
+  if (oflags & (_O_WTEXT | _O_U16TEXT | _O_U8TEXT))
   {
       LARGE_INTEGER size = {{0}};
 
@@ -2303,7 +2301,7 @@ int CDECL _wsopen_dispatch( const wchar_t* path, int oflags, int shflags, int pm
                   || creation==CREATE_ALWAYS || creation==TRUNCATE_EXISTING
                   || ((creation==OPEN_EXISTING || creation==OPEN_ALWAYS) && !size.QuadPart)))
       {
-          if (oflags & MSVCRT__O_U8TEXT)
+          if (oflags & _O_U8TEXT)
           {
               DWORD written = 0, tmp;
 
@@ -2347,11 +2345,11 @@ int CDECL _wsopen_dispatch( const wchar_t* path, int oflags, int shflags, int pm
   if (*fd == -1)
       return *_errno();
 
-  if (oflags & MSVCRT__O_WTEXT)
+  if (oflags & _O_WTEXT)
       get_ioinfo_nolock(*fd)->exflag |= EF_UTF16|EF_UNK_UNICODE;
-  else if (oflags & MSVCRT__O_U16TEXT)
+  else if (oflags & _O_U16TEXT)
       get_ioinfo_nolock(*fd)->exflag |= EF_UTF16;
-  else if (oflags & MSVCRT__O_U8TEXT)
+  else if (oflags & _O_U8TEXT)
       get_ioinfo_nolock(*fd)->exflag |= EF_UTF8;
 
   TRACE(":fd (%d) handle (%p)\n", *fd, hand);
@@ -2375,7 +2373,7 @@ int WINAPIV _wsopen( const wchar_t *path, int oflags, int shflags, ... )
   int pmode;
   int fd;
 
-  if (oflags & MSVCRT__O_CREAT)
+  if (oflags & _O_CREAT)
   {
     __ms_va_list ap;
 
@@ -2426,7 +2424,7 @@ int WINAPIV _sopen( const char *path, int oflags, int shflags, ... )
   int pmode;
   int fd;
 
-  if (oflags & MSVCRT__O_CREAT)
+  if (oflags & _O_CREAT)
   {
     __ms_va_list ap;
 
@@ -2447,16 +2445,16 @@ int WINAPIV _open( const char *path, int flags, ... )
 {
   __ms_va_list ap;
 
-  if (flags & MSVCRT__O_CREAT)
+  if (flags & _O_CREAT)
   {
     int pmode;
     __ms_va_start(ap, flags);
     pmode = va_arg(ap, int);
     __ms_va_end(ap);
-    return _sopen( path, flags, MSVCRT__SH_DENYNO, pmode );
+    return _sopen( path, flags, _SH_DENYNO, pmode );
   }
   else
-    return _sopen( path, flags, MSVCRT__SH_DENYNO);
+    return _sopen( path, flags, _SH_DENYNO);
 }
 
 /*********************************************************************
@@ -2466,16 +2464,16 @@ int WINAPIV _wopen(const wchar_t *path,int flags,...)
 {
   __ms_va_list ap;
 
-  if (flags & MSVCRT__O_CREAT)
+  if (flags & _O_CREAT)
   {
     int pmode;
     __ms_va_start(ap, flags);
     pmode = va_arg(ap, int);
     __ms_va_end(ap);
-    return _wsopen( path, flags, MSVCRT__SH_DENYNO, pmode );
+    return _wsopen( path, flags, _SH_DENYNO, pmode );
   }
   else
-    return _wsopen( path, flags, MSVCRT__SH_DENYNO);
+    return _wsopen( path, flags, _SH_DENYNO);
 }
 
 /*********************************************************************
@@ -2483,7 +2481,7 @@ int WINAPIV _wopen(const wchar_t *path,int flags,...)
  */
 int CDECL _creat(const char *path, int pmode)
 {
-  int flags = MSVCRT__O_CREAT | MSVCRT__O_TRUNC | MSVCRT__O_RDWR;
+  int flags = _O_CREAT | _O_TRUNC | _O_RDWR;
   return _open(path, flags, pmode);
 }
 
@@ -2492,7 +2490,7 @@ int CDECL _creat(const char *path, int pmode)
  */
 int CDECL _wcreat(const wchar_t *path, int pmode)
 {
-  int flags = MSVCRT__O_CREAT | MSVCRT__O_TRUNC | MSVCRT__O_RDWR;
+  int flags = _O_CREAT | _O_TRUNC | _O_RDWR;
   return _wopen(path, flags, pmode);
 }
 
@@ -2504,14 +2502,14 @@ int CDECL _open_osfhandle(intptr_t handle, int oflags)
   DWORD flags;
   int fd;
 
-  /* MSVCRT__O_RDONLY (0) always matches, so set the read flag
+  /* _O_RDONLY (0) always matches, so set the read flag
    * MFC's CStdioFile clears O_RDONLY (0)! if it wants to write to the
-   * file, so set the write flag. It also only sets MSVCRT__O_TEXT if it wants
-   * text - it never sets MSVCRT__O_BINARY.
+   * file, so set the write flag. It also only sets _O_TEXT if it wants
+   * text - it never sets _O_BINARY.
    */
   /* don't let split_oflags() decide the mode if no mode is passed */
-  if (!(oflags & (MSVCRT__O_BINARY | MSVCRT__O_TEXT)))
-      oflags |= MSVCRT__O_BINARY;
+  if (!(oflags & (_O_BINARY | _O_TEXT)))
+      oflags |= _O_BINARY;
 
   flags = GetFileType((HANDLE)handle);
   if (flags==FILE_TYPE_UNKNOWN && GetLastError()!=NO_ERROR)
@@ -2931,12 +2929,12 @@ int CDECL _read(int fd, void *buf, unsigned int count)
 int CDECL _setmode(int fd,int mode)
 {
     ioinfo *info = get_ioinfo(fd);
-    int ret = info->wxflag & WX_TEXT ? MSVCRT__O_TEXT : MSVCRT__O_BINARY;
-    if(ret==MSVCRT__O_TEXT && (info->exflag & (EF_UTF8|EF_UTF16)))
-        ret = MSVCRT__O_WTEXT;
+    int ret = info->wxflag & WX_TEXT ? _O_TEXT : _O_BINARY;
+    if(ret==_O_TEXT && (info->exflag & (EF_UTF8|EF_UTF16)))
+        ret = _O_WTEXT;
 
-    if(mode!=MSVCRT__O_TEXT && mode!=MSVCRT__O_BINARY && mode!=MSVCRT__O_WTEXT
-                && mode!=MSVCRT__O_U16TEXT && mode!=MSVCRT__O_U8TEXT) {
+    if(mode!=_O_TEXT && mode!=_O_BINARY && mode!=_O_WTEXT
+                && mode!=_O_U16TEXT && mode!=_O_U8TEXT) {
         *_errno() = EINVAL;
         release_ioinfo(info);
         return -1;
@@ -2947,7 +2945,7 @@ int CDECL _setmode(int fd,int mode)
         return EOF;
     }
 
-    if(mode == MSVCRT__O_BINARY) {
+    if(mode == _O_BINARY) {
         info->wxflag &= ~WX_TEXT;
         info->exflag &= ~(EF_UTF8|EF_UTF16);
         release_ioinfo(info);
@@ -2955,9 +2953,9 @@ int CDECL _setmode(int fd,int mode)
     }
 
     info->wxflag |= WX_TEXT;
-    if(mode == MSVCRT__O_TEXT)
+    if(mode == _O_TEXT)
         info->exflag &= ~(EF_UTF8|EF_UTF16);
-    else if(mode == MSVCRT__O_U8TEXT)
+    else if(mode == _O_U8TEXT)
         info->exflag = (info->exflag & ~EF_UTF16) | EF_UTF8;
     else
         info->exflag = (info->exflag & ~EF_UTF8) | EF_UTF16;
@@ -3017,10 +3015,10 @@ int CDECL _stat64(const char* path, struct _stat64 * buf)
 
   /* Dir, or regular file? */
   if (hfi.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
-    mode |= (MSVCRT__S_IFDIR | ALL_S_IEXEC);
+    mode |= (_S_IFDIR | ALL_S_IEXEC);
   else
   {
-    mode |= MSVCRT__S_IFREG;
+    mode |= _S_IFREG;
     /* executable? */
     if (plen > 6 && path[plen-4] == '.')  /* shortest exe: "\x.exe" */
     {
@@ -3169,10 +3167,10 @@ int CDECL _wstat64(const wchar_t* path, struct _stat64 * buf)
 
   /* Dir, or regular file? */
   if (hfi.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
-    mode |= (MSVCRT__S_IFDIR | ALL_S_IEXEC);
+    mode |= (_S_IFDIR | ALL_S_IEXEC);
   else
   {
-    mode |= MSVCRT__S_IFREG;
+    mode |= _S_IFREG;
     /* executable? */
     if (plen > 6 && path[plen-4] == '.')  /* shortest exe: "\x.exe" */
     {
@@ -3346,7 +3344,7 @@ int CDECL _umask(int umask)
  */
 int CDECL _utime64(const char* path, struct __utimbuf64 *t)
 {
-  int fd = _open(path, MSVCRT__O_WRONLY | MSVCRT__O_BINARY);
+  int fd = _open(path, _O_WRONLY | _O_BINARY);
 
   if (fd > 0)
   {
@@ -3378,7 +3376,7 @@ int CDECL _utime32(const char* path, struct __utimbuf32 *t)
  */
 int CDECL _wutime64(const wchar_t* path, struct __utimbuf64 *t)
 {
-  int fd = _wopen(path, MSVCRT__O_WRONLY | MSVCRT__O_BINARY);
+  int fd = _wopen(path, _O_WRONLY | _O_BINARY);
 
   if (fd > 0)
   {
@@ -4105,7 +4103,7 @@ FILE * CDECL _wfsopen(const wchar_t *path, const wchar_t *mode, int share)
       return NULL;
 
   LOCK_FILES();
-  fd = _wsopen(path, open_flags, share, MSVCRT__S_IREAD | MSVCRT__S_IWRITE);
+  fd = _wsopen(path, open_flags, share, _S_IREAD | _S_IWRITE);
   if (fd < 0)
     file = NULL;
   else if ((file = msvcrt_alloc_fp()) && msvcrt_init_fp(file, fd, stream_flags)
@@ -4157,7 +4155,7 @@ FILE * CDECL _fsopen(const char *path, const char *mode, int share)
  */
 FILE * CDECL fopen(const char *path, const char *mode)
 {
-    return _fsopen( path, mode, MSVCRT__SH_DENYNO );
+    return _fsopen( path, mode, _SH_DENYNO );
 }
 
 /*********************************************************************
@@ -4182,7 +4180,7 @@ int CDECL fopen_s(FILE** pFile,
  */
 FILE * CDECL _wfopen(const wchar_t *path, const wchar_t *mode)
 {
-    return _wfsopen( path, mode, MSVCRT__SH_DENYNO );
+    return _wfsopen( path, mode, _SH_DENYNO );
 }
 
 /*********************************************************************
@@ -4437,7 +4435,7 @@ FILE* CDECL _wfreopen(const wchar_t *path, const wchar_t *mode, FILE* file)
         fclose(file);
         if (msvcrt_get_flags(mode, &open_flags, &stream_flags) == -1)
             file = NULL;
-        else if((fd = _wopen(path, open_flags, MSVCRT__S_IREAD | MSVCRT__S_IWRITE)) < 0)
+        else if((fd = _wopen(path, open_flags, _S_IREAD | _S_IWRITE)) < 0)
             file = NULL;
         else if(msvcrt_init_fp(file, fd, stream_flags) == -1)
         {
@@ -5068,8 +5066,8 @@ FILE* CDECL tmpfile(void)
   FILE* file = NULL;
 
   LOCK_FILES();
-  fd = _open(filename, MSVCRT__O_CREAT | MSVCRT__O_BINARY | MSVCRT__O_RDWR | MSVCRT__O_TEMPORARY,
-          MSVCRT__S_IREAD | MSVCRT__S_IWRITE);
+  fd = _open(filename, _O_CREAT | _O_BINARY | _O_RDWR | _O_TEMPORARY,
+          _S_IREAD | _S_IWRITE);
   if (fd != -1 && (file = msvcrt_alloc_fp()))
   {
     if (msvcrt_init_fp(file, fd, _IORW) == -1)
diff --git a/dlls/msvcrt/heap.c b/dlls/msvcrt/heap.c
index 94b1f6a6b87..b74a759227a 100644
--- a/dlls/msvcrt/heap.c
+++ b/dlls/msvcrt/heap.c
@@ -847,7 +847,7 @@ int CDECL strncpy_s(char *dest, size_t numberOfElements,
     if (!MSVCRT_CHECK_PMT(src != NULL)) return EINVAL;
     if (!MSVCRT_CHECK_PMT(numberOfElements != 0)) return EINVAL;
 
-    if(count!=MSVCRT__TRUNCATE && count<numberOfElements)
+    if(count!=_TRUNCATE && count<numberOfElements)
         end = count;
     else
         end = numberOfElements-1;
@@ -855,7 +855,7 @@ int CDECL strncpy_s(char *dest, size_t numberOfElements,
     for(i=0; i<end && src[i]; i++)
         dest[i] = src[i];
 
-    if(!src[i] || end==count || count==MSVCRT__TRUNCATE) {
+    if(!src[i] || end==count || count==_TRUNCATE) {
         dest[i] = '\0';
         return 0;
     }
diff --git a/dlls/msvcrt/mbcs.c b/dlls/msvcrt/mbcs.c
index 7c9f359852d..cef67e71d47 100644
--- a/dlls/msvcrt/mbcs.c
+++ b/dlls/msvcrt/mbcs.c
@@ -2597,7 +2597,7 @@ int CDECL _mbstowcs_s_l(size_t *ret, wchar_t *wcstr,
         return EINVAL;
     }
 
-    if(count==MSVCRT__TRUNCATE || size<count)
+    if(count==_TRUNCATE || size<count)
         conv = size;
     else
         conv = count;
@@ -2605,7 +2605,7 @@ int CDECL _mbstowcs_s_l(size_t *ret, wchar_t *wcstr,
     conv = _mbstowcs_l(wcstr, mbstr, conv, locale);
     if(conv<size)
         wcstr[conv++] = '\0';
-    else if(conv==size && count==MSVCRT__TRUNCATE && wcstr[conv-1]!='\0') {
+    else if(conv==size && count==_TRUNCATE && wcstr[conv-1]!='\0') {
         wcstr[conv-1] = '\0';
         err = STRUNCATE;
     }else if(conv==size && wcstr[conv-1]!='\0') {
diff --git a/dlls/msvcrt/misc.c b/dlls/msvcrt/misc.c
index db8330f4b03..17019e9f5a7 100644
--- a/dlls/msvcrt/misc.c
+++ b/dlls/msvcrt/misc.c
@@ -59,7 +59,7 @@ int CDECL rand(void)
     /* this is the algorithm used by MSVC, according to
      * http://en.wikipedia.org/wiki/List_of_pseudorandom_number_generators */
     data->random_seed = data->random_seed * 214013 + 2531011;
-    return (data->random_seed >> 16) & MSVCRT_RAND_MAX;
+    return (data->random_seed >> 16) & RAND_MAX;
 }
 
 /*********************************************************************
@@ -406,7 +406,7 @@ unsigned int CDECL _set_output_format(unsigned int new_output_format)
 {
     unsigned int ret = output_format;
 
-    if(!MSVCRT_CHECK_PMT(new_output_format==0 || new_output_format==MSVCRT__TWO_DIGIT_EXPONENT))
+    if(!MSVCRT_CHECK_PMT(new_output_format==0 || new_output_format==_TWO_DIGIT_EXPONENT))
         return ret;
 
     output_format = new_output_format;
diff --git a/dlls/msvcrt/msvcrt.h b/dlls/msvcrt/msvcrt.h
index 5416dd9966e..cdb35456ecb 100644
--- a/dlls/msvcrt/msvcrt.h
+++ b/dlls/msvcrt/msvcrt.h
@@ -283,91 +283,19 @@ extern unsigned msvcrt_create_io_inherit_block(WORD*, BYTE**) DECLSPEC_HIDDEN;
 
 extern FILE MSVCRT__iob[];
 
-#define MSVCRT_RAND_MAX  0x7fff
-
 #define MSVCRT_NO_CONSOLE_FD (-2)
 #define MSVCRT_NO_CONSOLE ((HANDLE)MSVCRT_NO_CONSOLE_FD)
 
-#define MSVCRT_DRIVE_MAX    3
-#define MSVCRT_FNAME_MAX    256
-#define MSVCRT_DIR_MAX      256
-#define MSVCRT_EXT_MAX      256
-#define MSVCRT_PATH_MAX     260
 #define MSVCRT_stdin       (MSVCRT__iob+STDIN_FILENO)
 #define MSVCRT_stdout      (MSVCRT__iob+STDOUT_FILENO)
 #define MSVCRT_stderr      (MSVCRT__iob+STDERR_FILENO)
 
-#define MSVCRT__P_WAIT    0
-#define MSVCRT__P_NOWAIT  1
-#define MSVCRT__P_OVERLAY 2
-#define MSVCRT__P_NOWAITO 3
-#define MSVCRT__P_DETACH  4
-
-#define MSVCRT__OUT_TO_DEFAULT 0
-#define MSVCRT__OUT_TO_STDERR  1
-#define MSVCRT__OUT_TO_MSGBOX  2
-#define MSVCRT__REPORT_ERRMODE 3
-
 /* internal file._flag flags */
 #define MSVCRT__USERBUF  0x0100
 #define MSVCRT__IOCOMMIT 0x4000
 
-#define MSVCRT__S_IEXEC  0x0040
-#define MSVCRT__S_IWRITE 0x0080
-#define MSVCRT__S_IREAD  0x0100
-#define MSVCRT__S_IFIFO  0x1000
-#define MSVCRT__S_IFCHR  0x2000
-#define MSVCRT__S_IFDIR  0x4000
-#define MSVCRT__S_IFREG  0x8000
-#define MSVCRT__S_IFMT   0xF000
-
-#define MSVCRT__LK_UNLCK  0
-#define MSVCRT__LK_LOCK   1
-#define MSVCRT__LK_NBLCK  2
-#define MSVCRT__LK_RLCK   3
-#define MSVCRT__LK_NBRLCK 4
-
-#define	MSVCRT__SH_COMPAT	0x00	/* Compatibility */
-#define	MSVCRT__SH_DENYRW	0x10	/* Deny read/write */
-#define	MSVCRT__SH_DENYWR	0x20	/* Deny write */
-#define	MSVCRT__SH_DENYRD	0x30	/* Deny read */
-#define	MSVCRT__SH_DENYNO	0x40	/* Deny nothing */
-
-#define MSVCRT__O_RDONLY        0
-#define MSVCRT__O_WRONLY        1
-#define MSVCRT__O_RDWR          2
-#define MSVCRT__O_ACCMODE       (MSVCRT__O_RDONLY|MSVCRT__O_WRONLY|MSVCRT__O_RDWR)
-#define MSVCRT__O_APPEND        0x0008
-#define MSVCRT__O_RANDOM        0x0010
-#define MSVCRT__O_SEQUENTIAL    0x0020
-#define MSVCRT__O_TEMPORARY     0x0040
-#define MSVCRT__O_NOINHERIT     0x0080
-#define MSVCRT__O_CREAT         0x0100
-#define MSVCRT__O_TRUNC         0x0200
-#define MSVCRT__O_EXCL          0x0400
-#define MSVCRT__O_SHORT_LIVED   0x1000
-#define MSVCRT__O_TEXT          0x4000
-#define MSVCRT__O_BINARY        0x8000
-#define MSVCRT__O_RAW           MSVCRT__O_BINARY
-#define MSVCRT__O_WTEXT         0x10000
-#define MSVCRT__O_U16TEXT       0x20000
-#define MSVCRT__O_U8TEXT        0x40000
-
-#define MSVCRT_CLOCKS_PER_SEC 1000
-
-#define MSVCRT__TRUNCATE ((size_t)-1)
-
 #define _MAX__TIME64_T    (((__time64_t)0x00000007 << 32) | 0x93406FFF)
 
-/* _set_abort_behavior codes */
-#define MSVCRT__WRITE_ABORT_MSG    1
-#define MSVCRT__CALL_REPORTFAULT   2
-
-/* _get_output_format return code */
-#define MSVCRT__TWO_DIGIT_EXPONENT 0x1
-
-#define MSVCRT__NLSCMPERROR ((unsigned int)0x7fffffff)
-
 int __cdecl      MSVCRT_iswdigit(wint_t);
 
 int __cdecl      MSVCRT__fgetc_nolock(FILE*);
diff --git a/dlls/msvcrt/printf.h b/dlls/msvcrt/printf.h
index ec06162fa6d..c6c074de795 100644
--- a/dlls/msvcrt/printf.h
+++ b/dlls/msvcrt/printf.h
@@ -966,7 +966,7 @@ int FUNC_NAME(pf_printf)(FUNC_NAME(puts_clbk) pf_puts, void *puts_ctx, const API
     BOOL standard_rounding = options & _CRT_INTERNAL_PRINTF_STANDARD_ROUNDING;
 #else
     BOOL legacy_wide = TRUE, legacy_msvcrt_compat = TRUE;
-    BOOL three_digit_exp = _get_output_format() != MSVCRT__TWO_DIGIT_EXPONENT;
+    BOOL three_digit_exp = _get_output_format() != _TWO_DIGIT_EXPONENT;
     BOOL standard_rounding = FALSE;
 #endif
 
diff --git a/dlls/msvcrt/process.c b/dlls/msvcrt/process.c
index cd56d3992aa..cf1dcd3d279 100644
--- a/dlls/msvcrt/process.c
+++ b/dlls/msvcrt/process.c
@@ -27,6 +27,7 @@
  * -No check for maximum path/argument/environment size is done
  */
 
+#include <fcntl.h>
 #include <io.h>
 #include <process.h>
 #include <stdarg.h>
@@ -139,7 +140,7 @@ static intptr_t msvcrt_spawn(int flags, const wchar_t* exe, wchar_t* cmdline,
 
   TRACE("%x %s %s %s %d\n", flags, debugstr_w(exe), debugstr_w(cmdline), debugstr_w(env), use_path);
 
-  if ((unsigned)flags > MSVCRT__P_DETACH)
+  if ((unsigned)flags > _P_DETACH)
   {
     *_errno() = EINVAL;
     return -1;
@@ -150,7 +151,7 @@ static intptr_t msvcrt_spawn(int flags, const wchar_t* exe, wchar_t* cmdline,
   memset(&si, 0, sizeof(si));
   si.cb = sizeof(si);
   msvcrt_create_io_inherit_block(&si.cbReserved2, &si.lpReserved2);
-  if (flags == MSVCRT__P_DETACH) create_flags |= DETACHED_PROCESS;
+  if (flags == _P_DETACH) create_flags |= DETACHED_PROCESS;
   if (!CreateProcessW(fullname, cmdline, NULL, NULL, TRUE,
                       create_flags, env, NULL, &si, &pi))
   {
@@ -162,21 +163,21 @@ static intptr_t msvcrt_spawn(int flags, const wchar_t* exe, wchar_t* cmdline,
   free(si.lpReserved2);
   switch(flags)
   {
-  case MSVCRT__P_WAIT:
+  case _P_WAIT:
     WaitForSingleObject(pi.hProcess, INFINITE);
     GetExitCodeProcess(pi.hProcess,&pi.dwProcessId);
     CloseHandle(pi.hProcess);
     CloseHandle(pi.hThread);
     return pi.dwProcessId;
-  case MSVCRT__P_DETACH:
+  case _P_DETACH:
     CloseHandle(pi.hProcess);
     pi.hProcess = 0;
     /* fall through */
-  case MSVCRT__P_NOWAIT:
-  case MSVCRT__P_NOWAITO:
+  case _P_NOWAIT:
+  case _P_NOWAITO:
     CloseHandle(pi.hThread);
     return (intptr_t)pi.hProcess;
-  case  MSVCRT__P_OVERLAY:
+  case  _P_OVERLAY:
     _exit(0);
   }
   return -1; /* can't reach here */
@@ -398,7 +399,7 @@ intptr_t WINAPIV _wexecl(const wchar_t* name, const wchar_t* arg0, ...)
   args = msvcrt_valisttos(arg0, ap, ' ');
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, name, args, NULL, 0);
+  ret = msvcrt_spawn(_P_OVERLAY, name, args, NULL, 0);
 
   free(args);
   return ret;
@@ -422,7 +423,7 @@ intptr_t WINAPIV _execl(const char* name, const char* arg0, ...)
   args = msvcrt_valisttos_aw(arg0, ap, ' ');
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, nameW, args, NULL, 0);
+  ret = msvcrt_spawn(_P_OVERLAY, nameW, args, NULL, 0);
 
   free(nameW);
   free(args);
@@ -451,7 +452,7 @@ intptr_t WINAPIV _wexecle(const wchar_t* name, const wchar_t* arg0, ...)
   if (envp) envs = msvcrt_argvtos(envp, 0);
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, name, args, envs, 0);
+  ret = msvcrt_spawn(_P_OVERLAY, name, args, envs, 0);
 
   free(args);
   free(envs);
@@ -480,7 +481,7 @@ intptr_t WINAPIV _execle(const char* name, const char* arg0, ...)
   if (envp) envs = msvcrt_argvtos_aw(envp, 0);
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, nameW, args, envs, 0);
+  ret = msvcrt_spawn(_P_OVERLAY, nameW, args, envs, 0);
 
   free(nameW);
   free(args);
@@ -503,7 +504,7 @@ intptr_t WINAPIV _wexeclp(const wchar_t* name, const wchar_t* arg0, ...)
   args = msvcrt_valisttos(arg0, ap, ' ');
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, name, args, NULL, 1);
+  ret = msvcrt_spawn(_P_OVERLAY, name, args, NULL, 1);
 
   free(args);
   return ret;
@@ -527,7 +528,7 @@ intptr_t WINAPIV _execlp(const char* name, const char* arg0, ...)
   args = msvcrt_valisttos_aw(arg0, ap, ' ');
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, nameW, args, NULL, 1);
+  ret = msvcrt_spawn(_P_OVERLAY, nameW, args, NULL, 1);
 
   free(nameW);
   free(args);
@@ -556,7 +557,7 @@ intptr_t WINAPIV _wexeclpe(const wchar_t* name, const wchar_t* arg0, ...)
   if (envp) envs = msvcrt_argvtos(envp, 0);
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, name, args, envs, 1);
+  ret = msvcrt_spawn(_P_OVERLAY, name, args, envs, 1);
 
   free(args);
   free(envs);
@@ -585,7 +586,7 @@ intptr_t WINAPIV _execlpe(const char* name, const char* arg0, ...)
   if (envp) envs = msvcrt_argvtos_aw(envp, 0);
   __ms_va_end(ap);
 
-  ret = msvcrt_spawn(MSVCRT__P_OVERLAY, nameW, args, envs, 1);
+  ret = msvcrt_spawn(_P_OVERLAY, nameW, args, envs, 1);
 
   free(nameW);
   free(args);
@@ -600,7 +601,7 @@ intptr_t WINAPIV _execlpe(const char* name, const char* arg0, ...)
  */
 intptr_t CDECL _wexecv(const wchar_t* name, const wchar_t* const* argv)
 {
-  return _wspawnve(MSVCRT__P_OVERLAY, name, argv, NULL);
+  return _wspawnve(_P_OVERLAY, name, argv, NULL);
 }
 
 /*********************************************************************
@@ -611,7 +612,7 @@ intptr_t CDECL _wexecv(const wchar_t* name, const wchar_t* const* argv)
  */
 intptr_t CDECL _execv(const char* name, const char* const* argv)
 {
-  return _spawnve(MSVCRT__P_OVERLAY, name, argv, NULL);
+  return _spawnve(_P_OVERLAY, name, argv, NULL);
 }
 
 /*********************************************************************
@@ -621,7 +622,7 @@ intptr_t CDECL _execv(const char* name, const char* const* argv)
  */
 intptr_t CDECL _wexecve(const wchar_t* name, const wchar_t* const* argv, const wchar_t* const* envv)
 {
-  return _wspawnve(MSVCRT__P_OVERLAY, name, argv, envv);
+  return _wspawnve(_P_OVERLAY, name, argv, envv);
 }
 
 /*********************************************************************
@@ -632,7 +633,7 @@ intptr_t CDECL _wexecve(const wchar_t* name, const wchar_t* const* argv, const w
  */
 intptr_t CDECL _execve(const char* name, const char* const* argv, const char* const* envv)
 {
-  return _spawnve(MSVCRT__P_OVERLAY, name, argv, envv);
+  return _spawnve(_P_OVERLAY, name, argv, envv);
 }
 
 /*********************************************************************
@@ -642,7 +643,7 @@ intptr_t CDECL _execve(const char* name, const char* const* argv, const char* co
  */
 intptr_t CDECL _wexecvpe(const wchar_t* name, const wchar_t* const* argv, const wchar_t* const* envv)
 {
-  return _wspawnvpe(MSVCRT__P_OVERLAY, name, argv, envv);
+  return _wspawnvpe(_P_OVERLAY, name, argv, envv);
 }
 
 /*********************************************************************
@@ -653,7 +654,7 @@ intptr_t CDECL _wexecvpe(const wchar_t* name, const wchar_t* const* argv, const
  */
 intptr_t CDECL _execvpe(const char* name, const char* const* argv, const char* const* envv)
 {
-  return _spawnvpe(MSVCRT__P_OVERLAY, name, argv, envv);
+  return _spawnvpe(_P_OVERLAY, name, argv, envv);
 }
 
 /*********************************************************************
@@ -1054,7 +1055,7 @@ FILE* CDECL _wpopen(const wchar_t* command, const wchar_t* mode)
     return NULL;
 
   _get_fmode(&fmode);
-  textmode = fmode & (MSVCRT__O_BINARY | MSVCRT__O_TEXT);
+  textmode = fmode & (_O_BINARY | _O_TEXT);
   for (p = mode; *p; p++)
   {
     switch (*p)
@@ -1065,13 +1066,13 @@ FILE* CDECL _wpopen(const wchar_t* command, const wchar_t* mode)
         break;
       case 'B':
       case 'b':
-        textmode |= MSVCRT__O_BINARY;
-        textmode &= ~MSVCRT__O_TEXT;
+        textmode |= _O_BINARY;
+        textmode &= ~_O_TEXT;
         break;
       case 'T':
       case 't':
-        textmode |= MSVCRT__O_TEXT;
-        textmode &= ~MSVCRT__O_BINARY;
+        textmode |= _O_TEXT;
+        textmode &= ~_O_BINARY;
         break;
     }
   }
@@ -1120,7 +1121,7 @@ FILE* CDECL _wpopen(const wchar_t* command, const wchar_t* mode)
   wcscat(fullcmd, L" /c ");
   wcscat(fullcmd, command);
 
-  if ((container->proc = (HANDLE)msvcrt_spawn(MSVCRT__P_NOWAIT, comspec, fullcmd, NULL, 1))
+  if ((container->proc = (HANDLE)msvcrt_spawn(_P_NOWAIT, comspec, fullcmd, NULL, 1))
           == INVALID_HANDLE_VALUE)
   {
     _close(fds[fdToOpen]);
@@ -1252,7 +1253,7 @@ int CDECL _wsystem(const wchar_t* cmd)
   wcscat(fullcmd, L" /c ");
   wcscat(fullcmd, cmd);
 
-  res = msvcrt_spawn(MSVCRT__P_WAIT, comspec, fullcmd, NULL, 1);
+  res = msvcrt_spawn(_P_WAIT, comspec, fullcmd, NULL, 1);
 
   HeapFree(GetProcessHeap(), 0, comspec);
   HeapFree(GetProcessHeap(), 0, fullcmd);
diff --git a/dlls/msvcrt/string.c b/dlls/msvcrt/string.c
index edf6a5dd514..0c4c657ba99 100644
--- a/dlls/msvcrt/string.c
+++ b/dlls/msvcrt/string.c
@@ -1350,7 +1350,7 @@ int CDECL strncat_s( char* dst, size_t elem, const char* src, size_t count )
         {
             for(j = 0; (j + i) < elem; j++)
             {
-                if(count == MSVCRT__TRUNCATE && j + i == elem - 1)
+                if(count == _TRUNCATE && j + i == elem - 1)
                 {
                     dst[j + i] = '\0';
                     return STRUNCATE;
@@ -2656,7 +2656,7 @@ int __cdecl _strnicmp_l(const char *s1, const char *s2,
     int c1, c2;
 
     if(s1==NULL || s2==NULL)
-        return MSVCRT__NLSCMPERROR;
+        return _NLSCMPERROR;
 
     if(!count)
         return 0;
@@ -2766,7 +2766,7 @@ int __cdecl _memicmp_l(const void *v1, const void *v2, size_t len, _locale_t loc
     {
         if (len)
             MSVCRT_INVALID_PMT(NULL, EINVAL);
-        return len ? MSVCRT__NLSCMPERROR : 0;
+        return len ? _NLSCMPERROR : 0;
     }
 #endif
 
diff --git a/dlls/msvcrt/time.c b/dlls/msvcrt/time.c
index 0e69bec9916..60b8c8575d3 100644
--- a/dlls/msvcrt/time.c
+++ b/dlls/msvcrt/time.c
@@ -666,7 +666,7 @@ clock_t CDECL clock(void)
     LARGE_INTEGER systime;
 
     NtQuerySystemTime(&systime);
-    return (systime.QuadPart - init_time) / (TICKSPERSEC / MSVCRT_CLOCKS_PER_SEC);
+    return (systime.QuadPart - init_time) / (TICKSPERSEC / CLOCKS_PER_SEC);
 }
 
 /*********************************************************************
@@ -1381,7 +1381,7 @@ static size_t strftime_impl(STRFTIME_CHAR *str, size_t max,
 #else
                 if(_mbstowcs_s_l(&tmp, str+ret, max-ret,
                             mstm->tm_isdst ? tzname_dst : tzname_std,
-                            MSVCRT__TRUNCATE, loc) == STRUNCATE)
+                            _TRUNCATE, loc) == STRUNCATE)
                     ret = max;
 #endif
             ret += tmp-1;
diff --git a/dlls/msvcrt/wcs.c b/dlls/msvcrt/wcs.c
index e7722ae7b8d..9a30e0fe149 100644
--- a/dlls/msvcrt/wcs.c
+++ b/dlls/msvcrt/wcs.c
@@ -124,7 +124,7 @@ INT CDECL _wcsicmp_l(const wchar_t *str1, const wchar_t *str2, _locale_t locale)
     wchar_t c1, c2;
 
     if(!MSVCRT_CHECK_PMT(str1 != NULL) || !MSVCRT_CHECK_PMT(str2 != NULL))
-        return MSVCRT__NLSCMPERROR;
+        return _NLSCMPERROR;
 
     if(!locale)
         locale = get_current_locale_noalloc(&tmp);
@@ -170,7 +170,7 @@ INT CDECL _wcsnicmp_l(const wchar_t *str1, const wchar_t *str2,
         return 0;
 
     if(!MSVCRT_CHECK_PMT(str1 != NULL) || !MSVCRT_CHECK_PMT(str2 != NULL))
-        return MSVCRT__NLSCMPERROR;
+        return _NLSCMPERROR;
 
     if(!locale)
         locale = get_current_locale_noalloc(&tmp);
@@ -703,7 +703,7 @@ static int wcsrtombs_s_l(size_t *ret, char *mbstr, size_t size,
     if (!MSVCRT_CHECK_PMT(wcstr != NULL)) return EINVAL;
     if (!MSVCRT_CHECK_PMT(*wcstr != NULL)) return EINVAL;
 
-    if(count==MSVCRT__TRUNCATE || size<count)
+    if(count==_TRUNCATE || size<count)
         conv = size;
     else
         conv = count;
@@ -717,9 +717,9 @@ static int wcsrtombs_s_l(size_t *ret, char *mbstr, size_t size,
         err = *_errno();
     }else if(conv < size)
         mbstr[conv++] = '\0';
-    else if(conv==size && (count==MSVCRT__TRUNCATE || mbstr[conv-1]=='\0')) {
+    else if(conv==size && (count==_TRUNCATE || mbstr[conv-1]=='\0')) {
         mbstr[conv-1] = '\0';
-        if(count==MSVCRT__TRUNCATE)
+        if(count==_TRUNCATE)
             err = STRUNCATE;
     }else {
         MSVCRT_INVALID_PMT("mbstr[size] is too small", ERANGE);
@@ -969,7 +969,7 @@ static int CDECL vsnprintf_s_l_opt( char *str, size_t sizeOfBuffer,
     puts_clbk_str_a(&ctx, 1, &nullbyte);
 
     if(ret<0 || ret==len) {
-        if(count!=MSVCRT__TRUNCATE && count>sizeOfBuffer) {
+        if(count!=_TRUNCATE && count>sizeOfBuffer) {
             MSVCRT_INVALID_PMT("str[sizeOfBuffer] is too small", ERANGE);
             memset(str, 0, sizeOfBuffer);
         } else
@@ -999,7 +999,7 @@ static int vsnwprintf_s_l_opt( wchar_t *str, size_t sizeOfBuffer,
     puts_clbk_str_w(&ctx, 1, L"");
 
     if(ret<0 || ret==len) {
-        if(count!=MSVCRT__TRUNCATE && count>sizeOfBuffer) {
+        if(count!=_TRUNCATE && count>sizeOfBuffer) {
             MSVCRT_INVALID_PMT("str[sizeOfBuffer] is too small", ERANGE);
             memset(str, 0, sizeOfBuffer*sizeof(wchar_t));
         } else
@@ -2348,7 +2348,7 @@ INT CDECL wcsncpy_s( wchar_t* wcDest, size_t numElement, const wchar_t *wcSrc,
                             size_t count )
 {
     WCHAR *p = wcDest;
-    BOOL truncate = (count == MSVCRT__TRUNCATE);
+    BOOL truncate = (count == _TRUNCATE);
 
     if(!wcDest && !numElement && !count)
         return 0;
@@ -2447,7 +2447,7 @@ INT CDECL wcsncat_s(wchar_t *dst, size_t elem,
         return EINVAL;
     }
 
-    if (count == MSVCRT__TRUNCATE)
+    if (count == _TRUNCATE)
     {
         srclen = wcslen(src);
         if (srclen >= (elem - dststart))