GetOS

[WestSide]

function GetOS: string;
const
  cOsUnknown  = 'Unknown';
  cOsWin95    = 'Win95';
  cOsWin98    = 'Win98';
  cOsWin98SE  = 'W98SE';
  cOsWinME    = 'WinME';
  cOsWinNT3   = 'WinNT3';
  cOsWinNT4   = 'WinNT4';
  cOsWin2000  = 'Win2000';
  cOsXP       = 'WinXP';
  cOsVista    = 'WinVista';
  cOsSeven    = 'WinSeven';
var
  OS: TOSVersionInfo;
  majorVer, minorVer: Integer;
begin
  Result := cOsUnknown;
  OS.dwOSVersionInfoSize := SizeOf(TOSVersionInfo);

  if GetVersionEx(OS) then
  begin
    majorVer := OS.dwMajorVersion;
    minorVer := OS.dwMinorVersion;
    case OS.dwPlatformId of
      VER_PLATFORM_WIN32_NT: { Windows NT/2000/XP/Vista/Seven }
        begin
          // Windows 95      - 4 ; 0
          // Windows 98      - 4 ; 10
          // Windows Me      - 4 ; 90
          // Windows NT 3.51 - 3 ; 51
          // Windows NT 4.0  - 4 ; 0
          // Windows 2000    - 5 ; 0
          // Windows XP      - 5 ; 1
          if (majorVer=3) and (minorVer=51) then
            Result := cOsWinNT3
          else if (majorVer = 4) and (minorVer=0) then
            Result := cOsWinNT4
          else if (majorVer = 5) and (minorVer = 0) then
            Result := cOsWin2000
          else if (majorVer = 5) and (minorVer = 1) then
            Result := cOsXP
          else if (majorVer = 6) and (minorVer = 0) then
            Result := cOsVista
          else if (majorVer = 6) and (minorVer = 1) then
            Result := cOsSeven
          else
            Result := cOsUnknown;
        end;
      VER_PLATFORM_WIN32_WINDOWS:  { Windows 9x/ME }
        begin
          if (majorVer = 4) and (minorVer = 0) then
            Result := cOsWin95
          else if (majorVer = 4) and (minorVer = 10) then
          begin
            if OS.szCSDVersion[1] = 'A' then
              Result := cOsWin98SE
            else
              Result := cOsWin98;
          end
          else if (majorVer = 4) and (minorVer = 90) then
            Result := cOsWinME
          else
            Result := cOsUnknown;
        end;
      else
        Result := cOsUnknown;
    end;
  end
  else
    Result := cOsUnknown;
end;

Исправленная функция из Ounk.
Спасибо Dave и KpuMuHaJl за помощь в тестах.

[LeFF]

можно еще серверные оси добавить) но это канеш опционально...