diff --git a/dlls/ddraw/d3ddevice/mesa.c b/dlls/ddraw/d3ddevice/mesa.c
index bc4c43fafa4..159187218c9 100644
--- a/dlls/ddraw/d3ddevice/mesa.c
+++ b/dlls/ddraw/d3ddevice/mesa.c
@@ -3153,7 +3153,7 @@ d3ddevice_blt(IDirectDrawSurfaceImpl *This, LPRECT rdst,
 		x_stretch = (double) (rect.u3.x2 - rect.u1.x1) / (double) width;
 		y_stretch = (double) (rect.u4.y2 - rect.u2.y1) / (double) height;
 
-		TRACE(" using memory to buffer Blt overide.\n");
+		TRACE(" using memory to buffer Blt override.\n");
 
 		ENTER_GL();
 
@@ -3161,7 +3161,7 @@ d3ddevice_blt(IDirectDrawSurfaceImpl *This, LPRECT rdst,
 		
 		if (upload_surface_to_tex_memory_init(src_impl, 0, &gl_d3d_dev->current_internal_format,
 						      initial, ((dwFlags & DDBLT_KEYSRC) != 0), UNLOCK_TEX_SIZE, UNLOCK_TEX_SIZE) != DD_OK) {
-		    ERR(" unsupported pixel format at memory to buffer Blt overide.\n");
+		    ERR(" unsupported pixel format at memory to buffer Blt override.\n");
 		    LEAVE_GL();
 		    return DDERR_INVALIDPARAMS;
 		}
@@ -3172,7 +3172,7 @@ d3ddevice_blt(IDirectDrawSurfaceImpl *This, LPRECT rdst,
 		else
 		    glDrawBuffer(GL_BACK);
 
-		/* Now the serious stuff happens. This is basically the same code that for the memory
+		/* Now the serious stuff happens. This is basically the same code as for the memory
 		   flush to frame buffer ... with stretching and different rectangles added :-) */
 		for (y = 0; y < height; y += UNLOCK_TEX_SIZE) {
 		    RECT flush_rect;
@@ -3274,7 +3274,7 @@ d3ddevice_bltfast(IDirectDrawSurfaceImpl *This, DWORD dstx,
     
     if (setup_rect_and_surface_for_blt(This, &buffer_type, (D3DRECT *) &rdst) != DD_OK) return DDERR_INVALIDPARAMS;
 
-    TRACE(" using BltFast memory to frame buffer overide.\n");
+    TRACE(" using BltFast memory to frame buffer override.\n");
     
     ENTER_GL();
     
@@ -3283,7 +3283,7 @@ d3ddevice_bltfast(IDirectDrawSurfaceImpl *This, DWORD dstx,
     if (upload_surface_to_tex_memory_init(src_impl, 0, &gl_d3d_dev->current_internal_format,
 					  initial, (trans & DDBLTFAST_SRCCOLORKEY) != 0,
 					  UNLOCK_TEX_SIZE, UNLOCK_TEX_SIZE) != DD_OK) {
-	ERR(" unsupported pixel format at memory to buffer Blt overide.\n");
+	ERR(" unsupported pixel format at memory to buffer Blt override.\n");
 	LEAVE_GL();
 	return DDERR_INVALIDPARAMS;
     }
@@ -3978,9 +3978,9 @@ d3ddevice_create(IDirect3DDeviceImpl **obj, IDirectDrawImpl *d3d, IDirectDrawSur
 		surf2->aux_blt = d3ddevice_blt;
 		surf2->aux_bltfast = d3ddevice_bltfast;
 		
-		TRACE(" overiding direct surface access.\n");
+		TRACE(" overriding direct surface access.\n");
 	    } else {
-	        TRACE(" no overide.\n");
+	        TRACE(" no override.\n");
 	    }
 	    surf2->d3ddevice = object;
 	}
@@ -4172,7 +4172,7 @@ static void fill_caps(void)
     opengl_device_caps.dwReserved3 = 0;
     opengl_device_caps.dwReserved4 = 0;
 
-    /* And now some GL overides :-) */
+    /* And now some GL overrides :-) */
     glGetIntegerv(GL_MAX_TEXTURE_SIZE, (GLint *) &opengl_device_caps.dwMaxTextureWidth);
     opengl_device_caps.dwMaxTextureHeight = opengl_device_caps.dwMaxTextureWidth;
     opengl_device_caps.dwMaxTextureAspectRatio = opengl_device_caps.dwMaxTextureWidth;
diff --git a/dlls/ddraw/d3dtexture.c b/dlls/ddraw/d3dtexture.c
index 39f32ad0901..fdc8bc40aa6 100644
--- a/dlls/ddraw/d3dtexture.c
+++ b/dlls/ddraw/d3dtexture.c
@@ -889,7 +889,7 @@ HRESULT d3dtexture_create(IDirectDrawImpl *d3d, IDirectDrawSurfaceImpl *surf, BO
 	surf->aux_setcolorkey_cb = gltex_setcolorkey_cb;
 	surf->set_palette = gltex_set_palette;
 
-	/* We are the only one to use the aux_blt and aux_bltfast overides, so no need
+	/* We are the only one to use the aux_blt and aux_bltfast overrides, so no need
 	   to save those... */
 	surf->aux_blt = gltex_blt;
 	surf->aux_bltfast = gltex_bltfast;
diff --git a/dlls/ddraw/d3dviewport.c b/dlls/ddraw/d3dviewport.c
index 12fd1a2a161..fd04ef2fca9 100644
--- a/dlls/ddraw/d3dviewport.c
+++ b/dlls/ddraw/d3dviewport.c
@@ -198,7 +198,7 @@ Main_IDirect3DViewportImpl_3_2_1_SetViewport(LPDIRECT3DVIEWPORT3 iface,
     memset(&(This->viewports.vp1), 0, sizeof(This->viewports.vp1));
     memcpy(&(This->viewports.vp1), lpData, lpData->dwSize);
 
-    /* Tests on two games shows that these values are never used properly so overide
+    /* Tests on two games show that these values are never used properly so override
        them with proper ones :-)
     */
     This->viewports.vp1.dvMinZ = 0.0;
diff --git a/dlls/mapi32/prop.c b/dlls/mapi32/prop.c
index 665c01b3cd7..d4f02d1820c 100644
--- a/dlls/mapi32/prop.c
+++ b/dlls/mapi32/prop.c
@@ -1636,7 +1636,7 @@ IMAPIProp_fnSaveChanges(LPMAPIPROP iface, ULONG ulFlags)
  *           successfully.
  * NOTES
  *  - If MAPI_W_ERRORS_RETURNED is returned, any properties that could not be
- *    retrieved from iface are present in lppProps with thier type
+ *    retrieved from iface are present in lppProps with their type
  *    changed to PT_ERROR and Id unchanged.
  */
 static inline HRESULT WINAPI
@@ -1985,7 +1985,7 @@ IMAPIProp_fnCopyProps(LPMAPIPROP iface, LPSPropTagArray lpInclProps,
 /**************************************************************************
  *  IMAPIProp_GetNamesFromIDs {MAPI32}
  *
- * Get the names of properties from thier identifiers.
+ * Get the names of properties from their identifiers.
  *
  * PARAMS
  *  iface       [I]   IMAPIProp object to operate on
diff --git a/dlls/mapi32/tests/prop.c b/dlls/mapi32/tests/prop.c
index d72d7612ed0..2138032da76 100644
--- a/dlls/mapi32/tests/prop.c
+++ b/dlls/mapi32/tests/prop.c
@@ -636,7 +636,7 @@ static void test_PpropFindProp(void)
            ptTypes[i]);
 
         pRet = pPpropFindProp(&pvProp, 1u, i ? ptTypes[i-1] : ptTypes[i+1]);
-        ok(pRet == NULL, "PpropFindProp[%ld]: Found non-existing propery\n",
+        ok(pRet == NULL, "PpropFindProp[%ld]: Found non-existent propery\n",
            ptTypes[i]);
     }
 
@@ -868,11 +868,11 @@ static void test_LpValFindProp(void)
            ptTypes[i]);
 
         pRet = pLpValFindProp(PROP_TAG(ptTypes[i], 0u), 1u, &pvProp);
-        ok(pRet == NULL, "LpValFindProp[%ld]: Found non-existing propery id\n",
+        ok(pRet == NULL, "LpValFindProp[%ld]: Found non-existent propery id\n",
            ptTypes[i]);
 
         pRet = pLpValFindProp(PROP_TAG(PT_NULL, 0u), 1u, &pvProp);
-        ok(pRet == NULL, "LpValFindProp[%ld]: Found non-existing propery id/type\n",
+        ok(pRet == NULL, "LpValFindProp[%ld]: Found non-existent propery id/type\n",
            ptTypes[i]);
 
         pRet = pLpValFindProp(PROP_TAG(PT_NULL, 1u), 1u, &pvProp);
@@ -1257,22 +1257,22 @@ static void test_IProp(void)
     tags.aulPropTag[0] = PR_RESPONSE_REQUESTED;
     sc = IPropData_DeleteProps(lpIProp, (LPSPropTagArray)&tags, &lpProbs);
     ok(sc == E_ACCESSDENIED && !lpProbs,
-       "DeleteProps(non-existant): Expected E_ACCESSDENIED null got 0x%08lX %p\n",
+       "DeleteProps(non-existent): Expected E_ACCESSDENIED null got 0x%08lX %p\n",
        sc, lpProbs);
 
     /* Set access to read and write */
     sc = IPropData_HrSetObjAccess(lpIProp, IPROP_READWRITE);
     ok(sc == S_OK, "SetObjAcess(WRITE): Expected S_OK got 0x%08lX\n", sc);
 
-    /* Delete non existant item - No error */
+    /* Delete non-existent item - No error */
     lpProbs = NULL;
     tags.aulPropTag[0] = PR_RESPONSE_REQUESTED;
     sc = IPropData_DeleteProps(lpIProp, (LPSPropTagArray)&tags, &lpProbs);
     ok(sc == S_OK && !lpProbs,
-       "DeleteProps(non-existant): Expected S_OK null got 0x%08lX %p\n",
+       "DeleteProps(non-existent): Expected S_OK null got 0x%08lX %p\n",
        sc, lpProbs);
 
-    /* Delete existant item (r/o) - No error, but lpProbs populated */
+    /* Delete existing item (r/o) - No error, but lpProbs populated */
     lpProbs = NULL;
     tags.aulPropTag[0] = PR_IMPORTANCE;
     sc = IPropData_DeleteProps(lpIProp, (LPSPropTagArray)&tags, &lpProbs);
@@ -1318,7 +1318,7 @@ static void test_IProp(void)
     sc = IPropData_HrSetPropAccess(lpIProp, (LPSPropTagArray)&tags, access);
     ok(sc == S_OK, "SetPropAcess(WRITE): Expected S_OK got 0x%08lX\n", sc);
 
-    /* Delete existant item (r/w) - No error, no problems */
+    /* Delete existing item (r/w) - No error, no problems */
     lpProbs = NULL;
     sc = IPropData_DeleteProps(lpIProp, (LPSPropTagArray)&tags, &lpProbs);
     ok(sc == S_OK && !lpProbs,
diff --git a/dlls/msi/action.c b/dlls/msi/action.c
index 653edb8a7cc..11601d9a856 100644
--- a/dlls/msi/action.c
+++ b/dlls/msi/action.c
@@ -716,7 +716,7 @@ static void ui_actioninfo(MSIPACKAGE *package, LPCWSTR action, BOOL start,
  *  The arguments following count are a list of path segments.
  *  A path segment may be NULL.
  *
- *  Path segments will be added with a \ seperating them.
+ *  Path segments will be added with a \ separating them.
  *  A \ will not be added after the last segment, however if the
  *    last segment is NULL, then the last character will be a \
  * 
diff --git a/dlls/msi/tests/db.c b/dlls/msi/tests/db.c
index f8ae25f9d1b..09f553e3490 100644
--- a/dlls/msi/tests/db.c
+++ b/dlls/msi/tests/db.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005 Mike McCormack for Codeweavers
+ * Copyright (C) 2005 Mike McCormack for CodeWeavers
  *
  * A test program for MSI database files.
  *
diff --git a/dlls/msi/tests/record.c b/dlls/msi/tests/record.c
index 4f1202f72d0..de26e9d86c2 100644
--- a/dlls/msi/tests/record.c
+++ b/dlls/msi/tests/record.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005 Mike McCormack for Codeweavers
+ * Copyright (C) 2005 Mike McCormack for CodeWeavers
  *
  * A test program for MSI records
  *
diff --git a/include/oleauto.h b/include/oleauto.h
index 38e56d8d397..1b33756823e 100644
--- a/include/oleauto.h
+++ b/include/oleauto.h
@@ -207,7 +207,7 @@ HRESULT WINAPI VariantChangeTypeEx(VARIANT*,VARIANT*,LCID,USHORT,VARTYPE);
 #define VAR_TIMEVALUEONLY       0x001 /* Ignore date portion of VT_DATE */
 #define VAR_DATEVALUEONLY       0x002 /* Ignore time portion of VT_DATE */
 #define VAR_VALIDDATE           0x004
-#define VAR_CALENDAR_HIJRI      0x008 /* Use the Hijri calender */
+#define VAR_CALENDAR_HIJRI      0x008 /* Use the Hijri calendar */
 #define VAR_LOCALBOOL           0x010 /* VT_BOOL<->VT_BSTR: Use localised boolean text */
 #define VAR_FORMAT_NOSUBSTITUTE 0x020 /* Don't change format strings for un-coercable types */
 #define VAR_FOURDIGITYEARS      0x040 /* Always print years with 4 digits */