type 
  USERINFO = record 
    name: LPWSTR; 
    password: LPWSTR; 
    password_age: DWORD; 
    priv: DWORD; 
    home_dir: LPWSTR; 
    comment: LPWSTR; 
    flags: DWORD; 
    script_path: LPWSTR; 
  end; 
 
function NetUserEnum(ServerName: PWideChar; Level, Filter: DWORD; 
  var Buffer: Pointer; PrefMaxLen: DWORD; var EntriesRead, TotalEntries, 
  ResumeHandle: DWORD): Longword; stdcall; external 'netapi32.dll'; 
 
function NetApiBufferFree(pBuffer: PByte): Longint; stdcall; 
external 'netapi32.dll'; 
 
procedure users(usrstr: TStrings); 
var 
  NetApiStatus, Enties, Total, ResumeH: Cardinal; 
  Info: ^USERINFO; 
  Buffer: Pointer; 
  i: Integer; 
begin 
  ResumeH := 0; 
  usrstr.Clear; 
  repeat 
    NetApiStatus := NetUserEnum(nil, 1, 0, Buffer, 0, Enties, Total, ResumeH); 
    Info := Buffer; 
    for i := 1 to Enties do 
    begin 
      usrstr.Add(WideCharToString(Info^.name)); 
      Inc(Info); 
    end; 
    NetApiBufferFree(Buffer); 
  until (NetApiStatus <> ERROR_MORE_DATA); 
end; 

// Beispielaufruf 
 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
  users(ListBox1.Items); 
end;