diff --git a/dlls/dxdiagn/container.c b/dlls/dxdiagn/container.c
index 23178ea8272..5feb7c5d32e 100644
--- a/dlls/dxdiagn/container.c
+++ b/dlls/dxdiagn/container.c
@@ -20,6 +20,8 @@
  */
 
 #include "config.h"
+
+#define COBJMACROS
 #include "dxdiag_private.h"
 #include "wine/debug.h"
 #include "wine/unicode.h"
@@ -33,7 +35,7 @@ HRESULT WINAPI IDxDiagContainerImpl_QueryInterface(PDXDIAGCONTAINER iface, REFII
 
     if (IsEqualGUID(riid, &IID_IUnknown)
         || IsEqualGUID(riid, &IID_IDxDiagContainer)) {
-        IDxDiagContainerImpl_AddRef(iface);
+        IUnknown_AddRef(iface);
         *ppobj = This;
         return S_OK;
     }
@@ -42,7 +44,7 @@ HRESULT WINAPI IDxDiagContainerImpl_QueryInterface(PDXDIAGCONTAINER iface, REFII
     return E_NOINTERFACE;
 }
 
-ULONG WINAPI IDxDiagContainerImpl_AddRef(PDXDIAGCONTAINER iface) {
+static ULONG WINAPI IDxDiagContainerImpl_AddRef(PDXDIAGCONTAINER iface) {
     IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
     ULONG refCount = InterlockedIncrement(&This->ref);
 
@@ -53,7 +55,7 @@ ULONG WINAPI IDxDiagContainerImpl_AddRef(PDXDIAGCONTAINER iface) {
     return refCount;
 }
 
-ULONG WINAPI IDxDiagContainerImpl_Release(PDXDIAGCONTAINER iface) {
+static ULONG WINAPI IDxDiagContainerImpl_Release(PDXDIAGCONTAINER iface) {
     IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
     ULONG refCount = InterlockedDecrement(&This->ref);
 
@@ -69,7 +71,7 @@ ULONG WINAPI IDxDiagContainerImpl_Release(PDXDIAGCONTAINER iface) {
 }
 
 /* IDxDiagContainer Interface follow: */
-HRESULT WINAPI IDxDiagContainerImpl_GetNumberOfChildContainers(PDXDIAGCONTAINER iface, DWORD* pdwCount) {
+static HRESULT WINAPI IDxDiagContainerImpl_GetNumberOfChildContainers(PDXDIAGCONTAINER iface, DWORD* pdwCount) {
   IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
   TRACE("(%p)\n", iface);
   if (NULL == pdwCount) {
@@ -79,7 +81,7 @@ HRESULT WINAPI IDxDiagContainerImpl_GetNumberOfChildContainers(PDXDIAGCONTAINER
   return S_OK;
 }
 
-HRESULT WINAPI IDxDiagContainerImpl_EnumChildContainerNames(PDXDIAGCONTAINER iface, DWORD dwIndex, LPWSTR pwszContainer, DWORD cchContainer) {
+static HRESULT WINAPI IDxDiagContainerImpl_EnumChildContainerNames(PDXDIAGCONTAINER iface, DWORD dwIndex, LPWSTR pwszContainer, DWORD cchContainer) {
   IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
   IDxDiagContainerImpl_SubContainer* p = NULL;
   DWORD i = 0;
@@ -108,7 +110,7 @@ HRESULT WINAPI IDxDiagContainerImpl_EnumChildContainerNames(PDXDIAGCONTAINER ifa
   return E_INVALIDARG;
 }
 
-HRESULT WINAPI IDxDiagContainerImpl_GetChildContainerInternal(PDXDIAGCONTAINER iface, LPCWSTR pwszContainer, IDxDiagContainer** ppInstance) {
+static HRESULT WINAPI IDxDiagContainerImpl_GetChildContainerInternal(PDXDIAGCONTAINER iface, LPCWSTR pwszContainer, IDxDiagContainer** ppInstance) {
   IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
   IDxDiagContainerImpl_SubContainer* p = NULL;
 
@@ -123,7 +125,7 @@ HRESULT WINAPI IDxDiagContainerImpl_GetChildContainerInternal(PDXDIAGCONTAINER i
   return E_INVALIDARG;
 }
 
-HRESULT WINAPI IDxDiagContainerImpl_GetChildContainer(PDXDIAGCONTAINER iface, LPCWSTR pwszContainer, IDxDiagContainer** ppInstance) {
+static HRESULT WINAPI IDxDiagContainerImpl_GetChildContainer(PDXDIAGCONTAINER iface, LPCWSTR pwszContainer, IDxDiagContainer** ppInstance) {
   IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
   IDxDiagContainer* pContainer = NULL;
   LPWSTR tmp, orig_tmp;
@@ -165,7 +167,7 @@ on_error:
   return hr;
 }
 
-HRESULT WINAPI IDxDiagContainerImpl_GetNumberOfProps(PDXDIAGCONTAINER iface, DWORD* pdwCount) {
+static HRESULT WINAPI IDxDiagContainerImpl_GetNumberOfProps(PDXDIAGCONTAINER iface, DWORD* pdwCount) {
   IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
   TRACE("(%p)\n", iface);
   if (NULL == pdwCount) {
@@ -175,7 +177,7 @@ HRESULT WINAPI IDxDiagContainerImpl_GetNumberOfProps(PDXDIAGCONTAINER iface, DWO
   return S_OK;
 }
 
-HRESULT WINAPI IDxDiagContainerImpl_EnumPropNames(PDXDIAGCONTAINER iface, DWORD dwIndex, LPWSTR pwszPropName, DWORD cchPropName) {
+static HRESULT WINAPI IDxDiagContainerImpl_EnumPropNames(PDXDIAGCONTAINER iface, DWORD dwIndex, LPWSTR pwszPropName, DWORD cchPropName) {
   IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
   IDxDiagContainerImpl_Property* p = NULL;
   DWORD i = 0;
@@ -204,7 +206,7 @@ HRESULT WINAPI IDxDiagContainerImpl_EnumPropNames(PDXDIAGCONTAINER iface, DWORD
   return E_INVALIDARG;
 }
 
-HRESULT WINAPI IDxDiagContainerImpl_GetProp(PDXDIAGCONTAINER iface, LPCWSTR pwszPropName, VARIANT* pvarProp) {
+static HRESULT WINAPI IDxDiagContainerImpl_GetProp(PDXDIAGCONTAINER iface, LPCWSTR pwszPropName, VARIANT* pvarProp) {
   IDxDiagContainerImpl *This = (IDxDiagContainerImpl *)iface;
   IDxDiagContainerImpl_Property* p = NULL;
   FIXME("(%p, %s, %p)\n", iface, debugstr_w(pwszPropName), pvarProp);
diff --git a/dlls/dxdiagn/dxdiag_private.h b/dlls/dxdiagn/dxdiag_private.h
index 38242c5b12b..6449b32341a 100644
--- a/dlls/dxdiagn/dxdiag_private.h
+++ b/dlls/dxdiagn/dxdiag_private.h
@@ -53,15 +53,6 @@ struct IDxDiagProviderImpl {
   IDxDiagContainer* pRootContainer;
 };
 
-/* IUnknown: */
-extern HRESULT WINAPI IDxDiagProviderImpl_QueryInterface(PDXDIAGPROVIDER iface, REFIID riid, LPVOID *ppobj);
-extern ULONG WINAPI IDxDiagProviderImpl_AddRef(PDXDIAGPROVIDER iface);
-extern ULONG WINAPI IDxDiagProviderImpl_Release(PDXDIAGPROVIDER iface);
-
-/* IDxDiagProvider: */
-extern HRESULT WINAPI IDxDiagProviderImpl_Initialize(PDXDIAGPROVIDER iface, DXDIAG_INIT_PARAMS* pParams);
-extern HRESULT WINAPI IDxDiagProviderImpl_GetRootContainer(PDXDIAGPROVIDER iface, IDxDiagContainer** ppInstance);
-
 /* ---------------- */
 /* IDxDiagContainer  */
 /* ---------------- */
@@ -95,8 +86,6 @@ struct IDxDiagContainerImpl {
 
 /* IUnknown: */
 extern HRESULT WINAPI IDxDiagContainerImpl_QueryInterface(PDXDIAGCONTAINER iface, REFIID riid, LPVOID *ppobj);
-extern ULONG WINAPI IDxDiagContainerImpl_AddRef(PDXDIAGCONTAINER iface);
-
 /** Internal */
 extern HRESULT WINAPI IDxDiagContainerImpl_AddProp(PDXDIAGCONTAINER iface, LPCWSTR pwszPropName, VARIANT* pVarProp);
 extern HRESULT WINAPI IDxDiagContainerImpl_AddChildContainer(PDXDIAGCONTAINER iface, LPCWSTR pszContName, PDXDIAGCONTAINER pSubCont);
diff --git a/dlls/dxdiagn/provider.c b/dlls/dxdiagn/provider.c
index dd71bcfc542..3719cd4a669 100644
--- a/dlls/dxdiagn/provider.c
+++ b/dlls/dxdiagn/provider.c
@@ -35,13 +35,13 @@
 WINE_DEFAULT_DEBUG_CHANNEL(dxdiag);
 
 /* IDxDiagProvider IUnknown parts follow: */
-HRESULT WINAPI IDxDiagProviderImpl_QueryInterface(PDXDIAGPROVIDER iface, REFIID riid, LPVOID *ppobj)
+static HRESULT WINAPI IDxDiagProviderImpl_QueryInterface(PDXDIAGPROVIDER iface, REFIID riid, LPVOID *ppobj)
 {
     IDxDiagProviderImpl *This = (IDxDiagProviderImpl *)iface;
 
     if (IsEqualGUID(riid, &IID_IUnknown)
         || IsEqualGUID(riid, &IID_IDxDiagProvider)) {
-        IDxDiagProviderImpl_AddRef(iface);
+        IUnknown_AddRef(iface);
         *ppobj = This;
         return S_OK;
     }
@@ -50,7 +50,7 @@ HRESULT WINAPI IDxDiagProviderImpl_QueryInterface(PDXDIAGPROVIDER iface, REFIID
     return E_NOINTERFACE;
 }
 
-ULONG WINAPI IDxDiagProviderImpl_AddRef(PDXDIAGPROVIDER iface) {
+static ULONG WINAPI IDxDiagProviderImpl_AddRef(PDXDIAGPROVIDER iface) {
     IDxDiagProviderImpl *This = (IDxDiagProviderImpl *)iface;
     ULONG refCount = InterlockedIncrement(&This->ref);
 
@@ -61,7 +61,7 @@ ULONG WINAPI IDxDiagProviderImpl_AddRef(PDXDIAGPROVIDER iface) {
     return refCount;
 }
 
-ULONG WINAPI IDxDiagProviderImpl_Release(PDXDIAGPROVIDER iface) {
+static ULONG WINAPI IDxDiagProviderImpl_Release(PDXDIAGPROVIDER iface) {
     IDxDiagProviderImpl *This = (IDxDiagProviderImpl *)iface;
     ULONG refCount = InterlockedDecrement(&This->ref);
 
@@ -77,7 +77,7 @@ ULONG WINAPI IDxDiagProviderImpl_Release(PDXDIAGPROVIDER iface) {
 }
 
 /* IDxDiagProvider Interface follow: */
-HRESULT WINAPI IDxDiagProviderImpl_Initialize(PDXDIAGPROVIDER iface, DXDIAG_INIT_PARAMS* pParams) {
+static HRESULT WINAPI IDxDiagProviderImpl_Initialize(PDXDIAGPROVIDER iface, DXDIAG_INIT_PARAMS* pParams) {
     IDxDiagProviderImpl *This = (IDxDiagProviderImpl *)iface;
     TRACE("(%p,%p)\n", iface, pParams);
 
@@ -93,7 +93,7 @@ HRESULT WINAPI IDxDiagProviderImpl_Initialize(PDXDIAGPROVIDER iface, DXDIAG_INIT
     return S_OK;
 }
 
-HRESULT WINAPI IDxDiagProviderImpl_GetRootContainer(PDXDIAGPROVIDER iface, IDxDiagContainer** ppInstance) {
+static HRESULT WINAPI IDxDiagProviderImpl_GetRootContainer(PDXDIAGPROVIDER iface, IDxDiagContainer** ppInstance) {
   HRESULT hr = S_OK;
   IDxDiagProviderImpl *This = (IDxDiagProviderImpl *)iface;
   TRACE("(%p,%p)\n", iface, ppInstance);
@@ -142,7 +142,7 @@ HRESULT DXDiag_CreateDXDiagProvider(LPCLASSFACTORY iface, LPUNKNOWN punkOuter, R
  * @param szFilePath: usually GetSystemDirectoryW
  * @param szFileName: name of the dll without path
  */
-HRESULT DXDiag_AddFileDescContainer(IDxDiagContainer* pSubCont, const WCHAR* szFilePath, const WCHAR* szFileName) {
+static HRESULT DXDiag_AddFileDescContainer(IDxDiagContainer* pSubCont, const WCHAR* szFilePath, const WCHAR* szFileName) {
   HRESULT hr = S_OK;
   /**/
   static const WCHAR szSlashSep[] = {'\\',0};
@@ -229,7 +229,7 @@ HRESULT DXDiag_AddFileDescContainer(IDxDiagContainer* pSubCont, const WCHAR* szF
   return hr;
 }
 
-HRESULT DXDiag_InitDXDiagSystemInfoContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagSystemInfoContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   static const WCHAR dwDirectXVersionMajor[] = {'d','w','D','i','r','e','c','t','X','V','e','r','s','i','o','n','M','a','j','o','r',0};
   static const WCHAR dwDirectXVersionMinor[] = {'d','w','D','i','r','e','c','t','X','V','e','r','s','i','o','n','M','i','n','o','r',0};
@@ -271,7 +271,7 @@ HRESULT DXDiag_InitDXDiagSystemInfoContainer(IDxDiagContainer* pSubCont) {
   return hr;
 }
 
-HRESULT DXDiag_InitDXDiagSystemDevicesContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagSystemDevicesContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   /*
   static const WCHAR szDescription[] = {'s','z','D','e','s','c','r','i','p','t','i','o','n',0};
@@ -307,7 +307,7 @@ HRESULT DXDiag_InitDXDiagSystemDevicesContainer(IDxDiagContainer* pSubCont) {
   return hr;
 }
 
-HRESULT DXDiag_InitDXDiagLogicalDisksContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagLogicalDisksContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   /*
   static const WCHAR szDriveLetter[] = {'s','z','D','r','i','v','e','L','e','t','t','e','r',0};
@@ -339,7 +339,7 @@ HRESULT DXDiag_InitDXDiagLogicalDisksContainer(IDxDiagContainer* pSubCont) {
   */
   return hr;
 }
-HRESULT DXDiag_InitDXDiagDirectXFilesContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagDirectXFilesContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   /**/
   static const WCHAR ddraw_dll[] = {'d','d','r','a','w','.','d','l','l',0};
@@ -389,7 +389,7 @@ HRESULT DXDiag_InitDXDiagDirectXFilesContainer(IDxDiagContainer* pSubCont) {
   return hr;
 }
 
-HRESULT DXDiag_InitDXDiagDisplayContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagDisplayContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   /*
   static const WCHAR szDescription[] = {'s','z','D','e','s','c','r','i','p','t','i','o','n',0};
@@ -406,7 +406,7 @@ HRESULT DXDiag_InitDXDiagDisplayContainer(IDxDiagContainer* pSubCont) {
   return hr;
 }
 
-HRESULT DXDiag_InitDXDiagDirectSoundContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagDirectSoundContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   static const WCHAR DxDiag_SoundDevices[] = {'D','x','D','i','a','g','_','S','o','u','n','d','D','e','v','i','c','e','s',0};
   static const WCHAR DxDiag_SoundCaptureDevices[] = {'D','x','D','i','a','g','_','S','o','u','n','d','C','a','p','t','u','r','e','D','e','v','i','c','e','s',0};
@@ -423,15 +423,17 @@ HRESULT DXDiag_InitDXDiagDirectSoundContainer(IDxDiagContainer* pSubCont) {
   return hr;
 }
 
-HRESULT DXDiag_InitDXDiagDirectMusicContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagDirectMusicContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   return hr;
 }
-HRESULT DXDiag_InitDXDiagDirectInputContainer(IDxDiagContainer* pSubCont) {
+
+static HRESULT DXDiag_InitDXDiagDirectInputContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   return hr;
 }
-HRESULT DXDiag_InitDXDiagDirectPlayContainer(IDxDiagContainer* pSubCont) {
+
+static HRESULT DXDiag_InitDXDiagDirectPlayContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   return hr;
 }
@@ -458,7 +460,7 @@ struct REG_TYPE {
   DWORD dwOffsetMinor;
 };
 
-HRESULT DXDiag_InitDXDiagDirectShowFiltersContainer(IDxDiagContainer* pSubCont) {
+static HRESULT DXDiag_InitDXDiagDirectShowFiltersContainer(IDxDiagContainer* pSubCont) {
   HRESULT hr = S_OK;
   static const WCHAR szName[] = {'s','z','N','a','m','e',0};
   static const WCHAR szCatName[] = {'s','z','C','a','t','N','a','m','e',0};