Here is how to find out almost everything of windows versions.

regards

Ronald

function  IsWin31 : Boolean;
var OS : TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  Result := (Os.dwPlatformId = VER_PLATFORM_WIN32s);
end;

function  IsWin95 : Boolean;
var OS : TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result:=(OS.dwMajorVersion >= 4) and (OS.dwMinorVersion = 0) and (OS.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS);
end;

function IsWin95OSR2 : Boolean;
var
  OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result:=(OS.dwMajorVersion >= 4) and (OS.dwMinorVersion = 0) and (lo(OS.dwBuildNumber) > 1000) and (OS.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS);
end;

function  IsWinNT: Boolean;
var OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result:=OS.dwPlatformId=VER_PLATFORM_WIN32_NT;
end;

function IsWin98 : Boolean;
var OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result:=(OS.dwMajorVersion >= 4) and (OS.dwMinorVersion > 0) and (OS.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS);
end;

function  IsWin98se : Boolean;
var OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result:=(OS.dwMajorVersion >= 4) and (OS.dwMinorVersion > 0) and (lo(OS.dwBuildNumber) > 2000) and (OS.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS);
end;

function IsWin2000 : Boolean;
var OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result := (OS.dwMajorVersion >= 5) and (OS.dwPlatformId = VER_PLATFORM_WIN32_NT);
end;

function  IsWinXP : Boolean;
var OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result := (OS.dwMajorVersion >= 5) and (OS.dwMinorVersion >= 1) and (OS.dwPlatformId = VER_PLATFORM_WIN32_NT);
end;


function IsWinMe : Boolean;
var OS :TOSVersionInfo;
begin
  ZeroMemory(@OS,SizeOf(OS));
  OS.dwOSVersionInfoSize:=SizeOf(OS);
  GetVersionEx(OS);
  result:=(OS.dwMajorVersion >= 4) and (OS.dwMinorVersion >= 90) and (OS.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS);
end;


function GetNTType : String;
var r : TRegistry;
    ts : String;
begin

  Result := '[UNKNOWN]';

  if IsWinNT then
    begin
      r := TRegistry.Create;
      r.RootKey := HKEY_LOCAL_MACHINE;
      r.OpenKey('SYSTEM\CurrentControlSet\Control\ProductOptions',False);
      ts := AnsiUpperCase(R.ReadString('ProductType'));
      r.Free;
      if (ts = 'WINNT') then
        begin
          result := 'Workstation';
          if IsWin2000 then
            result := 'Professional';
        end
      else if (ts = 'SERVERNT') then
        begin
           result := 'Server';
         end
      else if (ts = 'LANMANNT') then
        begin
          result := 'Advanced Server';
        end;
    end;

end;