Windows Operating System Version

function WindowsVersion():string;

//steve10120@ic0de.org

var

  OSINFO: TOSVersionInfoEx;

begin

  OSINFO.dwOSVersionInfoSize := SizeOf(OSINFO);

  if GetVersionExA(OSINFO) then

  begin

    if (OSINFO.dwMajorVersion = 5) and (OSINFO.dwMinorVersion = 0) then

      Result := 'Windows 2000'

    else if (OSINFO.dwMajorVersion = 5) and (OSINFO.dwMinorVersion = 1) then

      Result := 'Windows XP'

    else if (OSINFO.dwMajorVersion = 5) and (OSINFO.dwMinorVersion = 2) and (GetSystemMetrics(SM_SERVERR2) = 0) then

      Result := 'Windows Server 2003'

    else if (OSINFO.dwMajorVersion = 5) and (OSINFO.dwMinorVersion = 2) and (GetSystemMetrics(SM_SERVERR2) <> 0) then

      Result := 'Windows Server 2003 R2'

    else if (OSINFO.dwMajorVersion = 6) and (OSINFO.dwMinorVersion = 0) and (OSINFO.wProductType = VER_NT_WORKSTATION) then

      Result := 'Windows Vista'

    else if (OSINFO.dwMajorVersion = 6) and (OSINFO.dwMinorVersion = 0) and (OSINFO.wProductType <> VER_NT_WORKSTATION) then

      Result := 'Windows Server 2008'

    else if (OSINFO.dwMajorVersion = 6) and (OSINFO.dwMinorVersion = 1) and (OSINFO.wProductType <> VER_NT_WORKSTATION) then

      Result := 'Windows Server 2008 R2'

    else if (OSINFO.dwMajorVersion = 6) and (OSINFO.dwMinorVersion = 1) and (OSINFO.wProductType = VER_NT_WORKSTATION) then

      Result := 'Windows 7'

    else

      Result := 'Unknown';

  end;

end;