function GetColorDepth:DWord;
var
   h:hDC;
begin
     Result:=0;
     try
        h:=GetDC(0);
        Result:=1 shl (GetDeviceCaps(h,PLANES)*
                GetDeviceCaps(h,BITSPIXEL));
     finally
            ReleaseDC(0,h);
     end;
end;