Xeno86, is there any dedicated thread for developers of KernelEx, or does the current thread suffice? I suggest you to keep some regression test suite which would be run every now and then (or at least every day). Just the way Wine project does this. They use the separate program called Winetest: http://test.winehq.org/data/ I just made some runs of it, and it seems to be missing some API functionality. It fails very early with some assert: the Winetest source says we fail inside some helper function: 134 static int running_on_visible_desktop (void) 135 { 136 HWND desktop; 137 HMODULE huser32 = GetModuleHandle("user32.dll"); 138 FARPROC pGetProcessWindowStation = GetProcAddress(huser32, "GetProcessWindowStation"); 139 FARPROC pGetUserObjectInformationA = GetProcAddress(huser32, "GetUserObjectInformationA"); 140 141 desktop = GetDesktopWindow(); 142 if (!GetWindowLongPtrW(desktop, GWLP_WNDPROC)) /* Win9x */ 143 return IsWindowVisible(desktop); 144 145 if (pGetProcessWindowStation && pGetUserObjectInformationA) 146 { 147 DWORD len; 148 HWINSTA wstation; 149 USEROBJECTFLAGS uoflags; 150 151 wstation = (HWINSTA)pGetProcessWindowStation(); 152 assert(pGetUserObjectInformationA(wstation, UOI_FLAGS, &uoflags, sizeof(uoflags), &len)); 153 return (uoflags.dwFlags & WSF_VISIBLE) != 0; 154 } 155 return IsWindowVisible(desktop); 156 } So it seems the GetUserObjectInformationA() call is the first one which could be put into KernelEx regression test (or into the very Winetest also, if it can work together with KernelEx in future:)