[Ziele]

--- API GetVersionEx ---
PlatformId:   Win32 on Windows NT.
MajorVersion: 5
MinorVersion: 1
BuildNumber:  2600
CSDVersion:   'Dodatek Service Pack. 1'



--- Delphi RTL ---
PlatformId:   System is Windows NT.
MajorVersion: 5
MinorVersion: 1
BuildNumber:  2600
CSDVersion:   'Dodatek Service Pack. 1'

ja używam tej funkcji, mi wystarcza

function GetSystem: String;
 var
  OSinfo: OSVERSIONINFO;
  OS: string;
begin

 OSinfo.dwOSVersionInfoSize := SizeOf(OSVERSIONINFO);
 GetVersionEx(OSinfo);

 case (OSinfo.dwPlatformId) of

  VER_PLATFORM_WIN32s: OS := 'WIN 3.1' ;

  VER_PLATFORM_WIN32_WINDOWS:
   case (OSinfo.dwMajorVersion + OSinfo.dwMinorVersion) of
    4: OS := 'Win 95' ;
    14: OS := 'Win 98' ;
    94: OS := 'Win Me' ;
    end;

  VER_PLATFORM_WIN32_NT:
   case (OSinfo.dwMajorVersion + OSinfo.dwMinorVersion) of
    54: OS := 'Win NT 3.51';
    4: OS := 'Win NT 4.0';
    5: OS := 'Win 2000';
    6: OS := 'Win XP';
    7: OS := 'Windows Server 2003';
    end;

  else OS := 'Nieznany';
  end;

Result := OS;

end;