This short function will return what version of windows the application is currently running on.
type
TWindowsVersion = (wvWin9x, wvWinNT, wvWin2k, wvWinXP);
function GetWindowsVersion: TWindowsVersion;
begin
Result := wvWin9x;
if Win32Platform = VER_PLATFORM_WIN32_NT then
case Win32MajorVersion of
3..4: Result := wvWinNT;
5: case Win32MinorVersion of
0: Result := wvWin2k;
1: Result := wvWinXP;
end;
end;
end;