diff --git a/reactos/include/reactos/win32k/ntuser.h b/reactos/include/reactos/win32k/ntuser.h
index 7d8973dff67..65c54b2c5a8 100644
--- a/reactos/include/reactos/win32k/ntuser.h
+++ b/reactos/include/reactos/win32k/ntuser.h
@@ -1181,13 +1181,13 @@ NtUserExcludeUpdateRgn(
   HDC hDC,
   HWND hWnd);
 
-DWORD
+BOOL
 NTAPI
 NtUserFillWindow(
-  DWORD Unknown0,
-  DWORD Unknown1,
-  DWORD Unknown2,
-  DWORD Unknown3);
+  HWND hWndPaint,
+  HWND hWndPaint1,
+  HDC  hDC,
+  HBRUSH hBrush);
 
 HICON
 NTAPI
@@ -1313,13 +1313,13 @@ NtUserGetControlBrush(
   HDC  hdc,
   UINT ctlType);
 
-DWORD
+HBRUSH
 NTAPI
 NtUserGetControlColor(
-  DWORD Unknown0,
-  DWORD Unknown1,
-  DWORD Unknown2,
-  DWORD Unknown3);
+   HWND hwndParent,
+   HWND hwnd,
+   HDC hdc,
+   UINT CtlMsg);
 
 DWORD
 NTAPI
@@ -1408,9 +1408,9 @@ NtUserGetImeInfoEx(
 DWORD
 NTAPI
 NtUserGetInternalWindowPos(
-  DWORD Unknown0,
-  DWORD Unknown1,
-  DWORD Unknown2);
+  HWND hwnd,
+  LPRECT rectWnd,
+  LPPOINT ptIcon);
 
 HKL
 NTAPI
@@ -1442,10 +1442,10 @@ DWORD
 NTAPI
 NtUserGetKeyNameText( LONG lParam, LPWSTR lpString, int nSize );
 
-DWORD
+SHORT
 NTAPI
 NtUserGetKeyState(
-  DWORD Unknown0);
+  INT VirtKey);
 
 BOOL
 NTAPI
@@ -2497,18 +2497,18 @@ NtUserUpdateInstance(
   DWORD Unknown1,
   DWORD Unknown2);
 
-DWORD
+BOOL
 NTAPI
 NtUserUpdateLayeredWindow(
-  DWORD Unknown0,
-  DWORD Unknown1,
-  DWORD Unknown2,
-  DWORD Unknown3,
-  DWORD Unknown4,
-  DWORD Unknown5,
-  DWORD Unknown6,
-  DWORD Unknown7,
-  DWORD Unknown8);
+  HWND hwnd,
+  HDC hdcDst,
+  POINT *pptDst,
+  SIZE *psize,
+  HDC hdcSrc,
+  POINT *pptSrc,
+  COLORREF crKey,
+  BLENDFUNCTION *pblend,
+  DWORD dwFlags);
 
 BOOL
 NTAPI
@@ -2705,7 +2705,7 @@ NtUserGetMonitorInfo(
 /* Should be done in usermode */
 HANDLE
 NTAPI
-NtUserGetProp(HWND hWnd, ATOM Atom);
+NtUserGetProp(HWND hWnd, ATOM Atom); // Done in both User/Kernel
 
 BOOL
 NTAPI
@@ -2829,7 +2829,7 @@ NtUserMonitorFromWindow(
 
 RTL_ATOM
 NTAPI
-NtUserRegisterClassEx(
+NtUserRegisterClassEx(   // Need to use NtUserRegisterClassExWOW.
    CONST WNDCLASSEXW* lpwcx,
    PUNICODE_STRING ClassName,
    PUNICODE_STRING MenuName,
diff --git a/reactos/subsystems/win32/win32k/ntuser/keyboard.c b/reactos/subsystems/win32/win32k/ntuser/keyboard.c
index b81f5295ebd..b2a95438ea3 100644
--- a/reactos/subsystems/win32/win32k/ntuser/keyboard.c
+++ b/reactos/subsystems/win32/win32k/ntuser/keyboard.c
@@ -361,10 +361,10 @@ DWORD FASTCALL UserGetKeyState(DWORD key)
 }
 
 
-DWORD
+SHORT
 STDCALL
 NtUserGetKeyState(
-   DWORD key)
+   INT key)
 {
    DECLARE_RETURN(DWORD);
 
diff --git a/reactos/subsystems/win32/win32k/ntuser/ntstubs.c b/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
index d1ac1c79bac..4affcd1c31a 100644
--- a/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
+++ b/reactos/subsystems/win32/win32k/ntuser/ntstubs.c
@@ -254,13 +254,17 @@ NtUserGetControlBrush(
    return 0;
 }
 
-DWORD
+
+/*
+ * Called from PaintRect, works almost like wine PaintRect16 but returns hBrush.
+ */
+HBRUSH
 STDCALL
 NtUserGetControlColor(
-   DWORD Unknown0,
-   DWORD Unknown1,
-   DWORD Unknown2,
-   DWORD Unknown3)
+   HWND hwndParent,
+   HWND hwnd, 
+   HDC hdc,
+   UINT CtlMsg) // Wine PaintRect: WM_CTLCOLORMSGBOX + hbrush
 {
    UNIMPLEMENTED
 
diff --git a/reactos/subsystems/win32/win32k/ntuser/window.c b/reactos/subsystems/win32/win32k/ntuser/window.c
index c71b3996900..77d3f8b97b5 100644
--- a/reactos/subsystems/win32/win32k/ntuser/window.c
+++ b/reactos/subsystems/win32/win32k/ntuser/window.c
@@ -2504,14 +2504,17 @@ NtUserEndDeferWindowPosEx(DWORD Unknown0,
 }
 
 
+/*
+ * FillWindow: Called from User; Dialog, Edit and ListBox procs during a WM_ERASEBKGND.
+ */
 /*
  * @unimplemented
  */
-DWORD STDCALL
-NtUserFillWindow(DWORD Unknown0,
-                 DWORD Unknown1,
-                 DWORD Unknown2,
-                 DWORD Unknown3)
+BOOL STDCALL
+NtUserFillWindow(HWND hWndPaint,
+                 HWND hWndPaint1,
+                 HDC  hDC,
+                 HBRUSH hBrush)
 {
    UNIMPLEMENTED
 
@@ -2949,9 +2952,9 @@ CLEANUP:
  * @unimplemented
  */
 DWORD STDCALL
-NtUserGetInternalWindowPos(DWORD Unknown0,
-                           DWORD Unknown1,
-                           DWORD Unknown2)
+NtUserGetInternalWindowPos( HWND hwnd,
+                            LPRECT rectWnd,
+                            LPPOINT ptIcon)
 {
    UNIMPLEMENTED
 
@@ -4490,16 +4493,18 @@ NtUserShowWindowAsync(HWND hWnd, LONG nCmdShow)
 /*
  * @unimplemented
  */
-DWORD STDCALL
-NtUserUpdateLayeredWindow(DWORD Unknown0,
-                          DWORD Unknown1,
-                          DWORD Unknown2,
-                          DWORD Unknown3,
-                          DWORD Unknown4,
-                          DWORD Unknown5,
-                          DWORD Unknown6,
-                          DWORD Unknown7,
-                          DWORD Unknown8)
+BOOL
+STDCALL
+NtUserUpdateLayeredWindow(
+   HWND hwnd,
+   HDC hdcDst,
+   POINT *pptDst,
+   SIZE *psize,
+   HDC hdcSrc,
+   POINT *pptSrc,
+   COLORREF crKey,
+   BLENDFUNCTION *pblend,
+   DWORD dwFlags)
 {
    UNIMPLEMENTED
 
@@ -4507,8 +4512,6 @@ NtUserUpdateLayeredWindow(DWORD Unknown0,
 }
 
 
-
-
 /*
  *    @implemented
  */