uses ShlObj, ShellApi; 
 
procedure ShowSpecialFolder(const FLR: Integer); 
var 
  IIDL: PItemIDList; 
  info: ShellExecuteInfo; 
begin 
  ShGetSpecialFolderLocation(Application.Handle, FLR, IIDL); 
  zeromemory(@info, sizeof(ShellExecuteInfo)); 
  with info do begin 
    cbSize := sizeof(ShellExecuteInfo); 
    nShow := sw_normal; 
    fMask := SEE_MASK_IDLIST; 
    lpIDList := IIDL; 
  end; 
  ShellExecuteEx(@info); 
end; 
 
procedure TForm1.Button4Click(Sender: TObject); 
begin 
  ShowSpecialFolder(CSIDL_COMMON_DESKTOPDIRECTORY);  // Desktop AllUsers 
end; 
 
(* 
CSIDL_ADMINTOOLS = $0030;
CSIDL_ALTSTARTUP = $001D;
CSIDL_APPDATA = $001A;
CSIDL_BITBUCKET = $000A;
CSIDL_CDBURN_AREA = $003B;
CSIDL_COMMON_ADMINTOOLS = $002F;
CSIDL_COMMON_ALTSTARTUP = $001E;
CSIDL_COMMON_APPDATA = $0023;
CSIDL_COMMON_DESKTOPDIRECTORY = $0019;
CSIDL_COMMON_DOCUMENTS = $002E
CSIDL_COMMON_FAVORITES = $001F;
CSIDL_COMMON_MUSIC = $0035;
CSIDL_COMMON_PICTURES = $0036;
CSIDL_COMMON_PROGRAMS = $0017;
CSIDL_COMMON_STARTMENU = $0016;
CSIDL_COMMON_STARTUP = $0018;
CSIDL_COMMON_TEMPLATES = $002D;
CSIDL_COMMON_VIDEO = $0037;
CSIDL_CONTROLS = $0003;
CSIDL_COOKIES = $0021;
CSIDL_DESKTOP = $0000;
CSIDL_DESKTOPDIRECTORY = $0010
CSIDL_DESKTOPDIRECTORY = $0010;
CSIDL_DRIVES = $0011;
CSIDL_FAVORITES = $0006;
CSIDL_FLAG_CREATE = $8000;
CSIDL_FONTS = $0014;
CSIDL_HISTORY = $0022;
CSIDL_INTERNET = $0001;
CSIDL_INTERNET_CACHE = $0020;
CSIDL_LOCAL_APPDATA = $001C
CSIDL_MYDOCUMENTS = $000C
CSIDL_MYMUSIC = $000D;
CSIDL_MYPICTURES = $0027;
CSIDL_MYVIDEO = $000E;
CSIDL_NETHOOD = $0013;
CSIDL_NETWORK = $0012;
CSIDL_PERSONAL = $0005;
CSIDL_PRINTERS = $0004;
CSIDL_PRINTHOOD = $001B;
CSIDL_PROFILE = $0028;
CSIDL_PROFILES = $003E;
CSIDL_PROGRAM_FILES = $0026;
CSIDL_PROGRAM_FILES_COMMON = $002B;
CSIDL_PROGRAMS = $0002;
CSIDL_RECENT = $0008;
CSIDL_SENDTO = $0009;
CSIDL_STARTMENU = $000B;
CSIDL_STARTUP = $0007
CSIDL_STARTUP = $0007;
CSIDL_SYSTEM = $0025;
CSIDL_TEMPLATES = $0015;
CSIDL_WINDOWS = $0024;
*)