unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, CommDlg;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
type
  TOSVersion = (osUnknown, os95, os95OSR2, os98, os98SE, osNT3, osNT4, os2K, osME, osXP);

var
  Form1: TForm1;

implementation

{$R *.DFM}

function GetOS :TOSVersion;
var
  OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  Result:=osUnknown;
  if OS.dwPlatformId=VER_PLATFORM_WIN32_NT then begin
    case OS.dwMajorVersion of
      3: Result:=osNT3;
      4: Result:=osNT4;
      5: Result:=os2K;
    end;
    if (OS.dwMajorVersion=5) and (OS.dwMinorVersion=1) then
      Result:=osXP;
  end else begin
    if (OS.dwMajorVersion=4) and (OS.dwMinorVersion=0) then begin
      Result:=os95;
      if (Trim(OS.szCSDVersion)='B') then
        Result:=os95OSR2;
    end else
      if (OS.dwMajorVersion=4) and (OS.dwMinorVersion=10) then begin
        Result:=os98;
        if (Trim(OS.szCSDVersion)='A') then
          Result:=os98SE;
      end else
        if (OS.dwMajorVersion=4) and (OS.dwMinorVersion=90) then
          Result:=osME;
  end;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
os:TosVersion;
osVersion:string;
begin
  os:=Getos;
      case OS of
    os95, os95OSR2: OSVersion:='Windows 95';
    os98: OSVersion:='Windows 98';
    os98SE: OSVersion:='Windows 98 第二版';
    osME: OSVersion:='Windows Millenium Edition';
    osNT3, osNT4: OSVersion:='Windows NT';
    os2K: OSVersion:='Windows 2000';
    osXP: OSVersion:='Windows XP';
  end;
   showmessage(osversion);
end;

end.