Как найти каталог Windows?

Вариант 1:

Author: Vit

function GetWindowsFolder:string;

var p:PChar;
begin
  GetMem(p, MAX_PATH);
  result:='';
  if GetWindowsDirectory(p, MAX_PATH)>0 then
    result:=string(p);
  FreeMem(p);
end;

Вариант 2:

Source: DelphiWorld 6.0 https://delphiworld.narod.ru/

public
  { Public declarations }
  Windir: string;
  WindirP: PChar;
  Res: Cardinal;

procedure TForm1.Button1Click(Sender: TObject);
begin
  WinDirP := StrAlloc(MAX_PATH);
  Res := GetWindowsDirectory(WinDirP, MAX_PATH);
  if Res > 0 then
    WinDir := StrPas(WinDirP);
  Label1.Caption := WinDir;
end;