WindowsVersion/ru

uses
  Windows, SysUtils, ...;
  ...
{
Значение номеров версий Windows:
5.0 => Windows 2000
5.1 => Windows XP
5.2 => Windows XP64 или Windows 2003 Server
6.0 => Windows Vista или Windows 2008 Server
6.1 => Windows 7 или Windows 2008 Server R2
6.2 => Windows 8 или Windows Server 2012
6.3 => Windows 8.1 или Windows Server 2012 RS
}

function funGetWinVer: string;
// Возвращает номер версии Windows в виде строки
begin
  Result := IntToStr(LOBYTE(LOWORD(GetVersion)));
  Result := Result + '.';
  Result := Result + IntToStr(HIBYTE(LOWORD(GetVersion)));
end;

program EchoWinVersion;
uses sysutils;
...
begin
  Writeln('Win32 Platform    : ', Win32Platform    );
  Writeln('Win32 Major Version: ', Win32MajorVersion);
  Writeln('Win32 Minor Version: ', Win32MinorVersion);
  Writeln('Win32 Build Number : ', Win32BuildNumber );
  Writeln('Win32 CSD Version  : ', Win32CSDVersion  );
  readln;
end.

Win32 Platform    : 2
Win32 Major Version: 6
Win32 Minor Version: 1
Win32 Build Number : 7601
Win32 CSD Version  : Service Pack 1

Win32 Platform    : 2
Win32 Major Version: 6
Win32 Minor Version: 2
Win32 Build Number : 9200
Win32 CSD Version  :

...
Uses ..., Win32Proc;
...

Procedure GetWinVer;
Begin
if WindowsVersion = wv95 then Memo.Lines.Add('Windows 95')
  else if WindowsVersion = wvNT4 then Memo.Lines.Add('Windows NT v.4')
  else if WindowsVersion = wv98 then Memo.Lines.Add('Windows 98')
  else if WindowsVersion = wvMe then Memo.Lines.Add('Windows ME')
  else if WindowsVersion = wv2000 then Memo.Lines.Add('Windows 2000')
  else if WindowsVersion = wvXP then Memo.Lines.Add('Windows XP')
  else if WindowsVersion = wvServer2003 then Memo.Lines.Add('Windows Server 2003/Windows XP64')
  else if WindowsVersion = wvVista then Memo.Lines.Add('Windows Vista')
  else if WindowsVersion = wv7 then Memo.Lines.Add('Windows 7')
  else if WindowsVersion = wv10 then Memo.Lines.Add('Windows 10')
  else Memo.Lines.Add('Windows Unknown Version!');         
End.