diff --git a/dlls/msctf/categorymgr.c b/dlls/msctf/categorymgr.c
index 23580724286..648352af85a 100644
--- a/dlls/msctf/categorymgr.c
+++ b/dlls/msctf/categorymgr.c
@@ -168,9 +168,67 @@ static HRESULT WINAPI CategoryMgr_EnumItemsInCategory ( ITfCategoryMgr *iface,
 static HRESULT WINAPI CategoryMgr_FindClosestCategory ( ITfCategoryMgr *iface,
         REFGUID rguid, GUID *pcatid, const GUID **ppcatidList, ULONG ulCount)
 {
+    static const WCHAR fmt[] = { '%','s','\\','%','s','\\','C','a','t','e','g','o','r','y','\\','I','t','e','m','\\','%','s',0};
+
+    WCHAR fullkey[110];
+    WCHAR buf[39];
+    HKEY key;
+    HRESULT hr = S_FALSE;
+    INT index = 0;
     CategoryMgr *This = (CategoryMgr*)iface;
-    FIXME("STUB:(%p)\n",This);
-    return E_NOTIMPL;
+
+    TRACE("(%p)\n",This);
+
+    if (!pcatid || (ulCount && ppcatidList == NULL))
+        return E_INVALIDARG;
+
+    StringFromGUID2(rguid, buf, 39);
+    sprintfW(fullkey,fmt,szwSystemTIPKey,buf,buf);
+    *pcatid = GUID_NULL;
+
+    if (RegOpenKeyExW(HKEY_LOCAL_MACHINE,fullkey, 0, KEY_READ, &key ) !=
+            ERROR_SUCCESS)
+        return S_FALSE;
+
+    while (1)
+    {
+        HRESULT hr2;
+        ULONG res;
+        GUID guid;
+        WCHAR catid[39];
+        DWORD cName;
+
+        cName = 39;
+        res = RegEnumKeyExW(key, index, catid, &cName, NULL, NULL, NULL, NULL);
+        if (res != ERROR_SUCCESS && res != ERROR_MORE_DATA) break;
+        index ++;
+
+        hr2 = CLSIDFromString(catid, &guid);
+        if (FAILED(hr2)) continue;
+
+        if (ulCount)
+        {
+            int j;
+            BOOL found = FALSE;
+            for (j = 0; j < ulCount; j++)
+                if (IsEqualGUID(&guid, ppcatidList[j]))
+                {
+                    found = TRUE;
+                    *pcatid = guid;
+                    hr = S_OK;
+                    break;
+                }
+            if (found) break;
+        }
+        else
+        {
+            *pcatid = guid;
+            hr = S_OK;
+            break;
+        }
+    }
+
+    return hr;
 }
 
 static HRESULT WINAPI CategoryMgr_RegisterGUIDDescription (
diff --git a/dlls/msctf/tests/inputprocessor.c b/dlls/msctf/tests/inputprocessor.c
index b7e2695b38d..2d324138f5a 100644
--- a/dlls/msctf/tests/inputprocessor.c
+++ b/dlls/msctf/tests/inputprocessor.c
@@ -128,6 +128,8 @@ static void test_RegisterCategory(void)
     HRESULT hr;
     hr = ITfCategoryMgr_RegisterCategory(g_cm, &CLSID_FakeService, &GUID_TFCAT_TIP_KEYBOARD, &CLSID_FakeService);
     ok(SUCCEEDED(hr),"ITfCategoryMgr_RegisterCategory failed\n");
+    hr = ITfCategoryMgr_RegisterCategory(g_cm, &CLSID_FakeService, &GUID_TFCAT_DISPLAYATTRIBUTEPROVIDER, &CLSID_FakeService);
+    ok(SUCCEEDED(hr),"ITfCategoryMgr_RegisterCategory failed\n");
 }
 
 static void test_UnregisterCategory(void)
@@ -135,6 +137,27 @@ static void test_UnregisterCategory(void)
     HRESULT hr;
     hr = ITfCategoryMgr_UnregisterCategory(g_cm, &CLSID_FakeService, &GUID_TFCAT_TIP_KEYBOARD, &CLSID_FakeService);
     todo_wine ok(SUCCEEDED(hr),"ITfCategoryMgr_UnregisterCategory failed\n");
+    hr = ITfCategoryMgr_UnregisterCategory(g_cm, &CLSID_FakeService, &GUID_TFCAT_DISPLAYATTRIBUTEPROVIDER, &CLSID_FakeService);
+    todo_wine ok(SUCCEEDED(hr),"ITfCategoryMgr_UnregisterCategory failed\n");
+}
+
+static void test_FindClosestCategory(void)
+{
+    GUID output;
+    HRESULT hr;
+    const GUID *list[3] = {&GUID_TFCAT_TIP_SPEECH, &GUID_TFCAT_TIP_KEYBOARD, &GUID_TFCAT_TIP_HANDWRITING};
+
+    hr = ITfCategoryMgr_FindClosestCategory(g_cm, &CLSID_FakeService, &output, NULL, 0);
+    ok(SUCCEEDED(hr),"ITfCategoryMgr_FindClosestCategory failed (%x)\n",hr);
+    ok(IsEqualGUID(&output,&GUID_TFCAT_DISPLAYATTRIBUTEPROVIDER),"Wrong GUID\n");
+
+    hr = ITfCategoryMgr_FindClosestCategory(g_cm, &CLSID_FakeService, &output, list, 1);
+    ok(SUCCEEDED(hr),"ITfCategoryMgr_FindClosestCategory failed (%x)\n",hr);
+    ok(IsEqualGUID(&output,&GUID_NULL),"Wrong GUID\n");
+
+    hr = ITfCategoryMgr_FindClosestCategory(g_cm, &CLSID_FakeService, &output, list, 3);
+    ok(SUCCEEDED(hr),"ITfCategoryMgr_FindClosestCategory failed (%x)\n",hr);
+    ok(IsEqualGUID(&output,&GUID_TFCAT_TIP_KEYBOARD),"Wrong GUID\n");
 }
 
 START_TEST(inputprocessor)
@@ -146,6 +169,7 @@ START_TEST(inputprocessor)
         test_RegisterCategory();
         test_EnumInputProcessorInfo();
         test_EnumLanguageProfiles();
+        test_FindClosestCategory();
         test_UnregisterCategory();
         test_Unregister();
     }