[Alegun]

Повторюсь, используйте LoadBitmap

Код:

program Fon;
uses Windows, Messages;

function MainWndProc(Window: HWnd; AMessage, WParam, LParam: Longint): Longint; stdcall;
begin
 if AMessage = WM_DESTROY then
   begin
    PostQuitMessage(0);
    Result:= 0;
    Exit;
   end else
    Result:= DefWindowProc(Window, AMessage, WParam, LParam);
end;

{$R resources.res}
function InitApplication: Boolean;
var
 wcx: TWndClass;
 bmp: HBitmap;
begin
 bmp:= LoadBitmap(hInstance,MAKEINTRESOURCE('FON'));
 wcx.style:= CS_HREDRAW or CS_VREDRAW;
 wcx.lpfnWndProc:= @MainWndProc;
 wcx.cbClsExtra:= 0;
 wcx.cbWndExtra:= 0;
 wcx.hInstance:= hInstance;
 wcx.hIcon:= LoadIcon(0, IDI_APPLICATION);
 wcx.hCursor:= LoadCursor(0, IDC_ARROW);
 wcx.hbrBackground:= CreatePatternBrush(bmp);
 wcx.lpszClassName:= PChar('MainWClass');
 Result:= RegisterClass(wcx) <> 0;
end;

function InitInstance: HWND;
begin
 Result:= CreateWindow(PChar('MainWClass'),'Пример', WS_OVERLAPPEDWINDOW,
 Integer(CW_USEDEFAULT), Integer(CW_USEDEFAULT), Integer(CW_USEDEFAULT),
 Integer(CW_USEDEFAULT), 0, 0, hInstance, nil);
end;

var
 hwndMain: HWND;
 AMessage: msg;
begin
 if (not InitApplication) then
   MessageBox(0, 'Ошибка регистрации окна', nil, mb_Ok)
else
begin
   hwndMain := InitInstance;
   if (hwndMain = 0) then
     MessageBox(0, 'Ошибка создания окна', nil, mb_Ok)
   else
   begin
     ShowWindow(hwndMain, CmdShow);
     UpdateWindow(hwndMain);
     while (GetMessage(AMessage, 0, 0, 0)) do
     begin
       TranslateMessage(AMessage);
       DispatchMessage(AMessage);
     end;
   end;
end;

end.