System Delphi

Title: Getting the Windows version in code?
Question: How do I retrieve the Windows version in code?
Answer:
Here is an example that should work under all versions of Windows.
{$IFDEF WIN32}
function GetVersionEx(lpOs : pointer) : BOOL; stdcall;
external 'kernel32' name 'GetVersionExA';
{$ENDIF}
procedure GetWindowsVersion(var Major : integer;
var Minor : integer);
var
{$IFDEF WIN32}
lpOS, lpOS2 : POsVersionInfo;
{$ELSE}
l : longint;
{$ENDIF}
begin
{$IFDEF WIN32}
GetMem(lpOS, SizeOf(TOsVersionInfo));
lpOs^.dwOSVersionInfoSize := SizeOf(TOsVersionInfo);
while getVersionEx(lpOS) = false do begin
GetMem(lpos2, lpos^.dwOSVersionInfoSize + 1);
lpOs2^.dwOSVersionInfoSize := lpOs^.dwOSVersionInfoSize + 1;
FreeMem(lpOs, lpOs^.dwOSVersionInfoSize);
lpOS := lpOs2;
end;
Major := lpOs^.dwMajorVersion;
Minor := lpOs^.dwMinorVersion;
FreeMem(lpOs, lpOs^.dwOSVersionInfoSize);
{$ELSE}
l := GetVersion;
Major := LoByte(LoWord(l));
Minor := HiByte(LoWord(l));
{$ENDIF}
end;
procedure TForm1.Button1Click(Sender: TObject);
var
Major : integer;
Minor : integer;
begin
GetWindowsVersion(Major, Minor);
Memo1.Lines.Add(IntToStr(Major));
Memo1.Lines.Add(IntToStr(Minor));
end;