unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Buttons, ComCtrls;

type
USER_INFO_1 = record
    usri1_name: LPWSTR;
    usri1_password: LPWSTR;
    usri1_password_age: DWORD;
    usri1_priv: DWORD;
    usri1_home_dir: LPWSTR;
    usri1_comment: LPWSTR;
    usri1_flags: DWORD;
    usri1_script_path: LPWSTR;
  end;
lpUSER_INFO_1 = ^USER_INFO_1;
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';

type
  TForm1 = class(TForm)
    BitBtn1: TBitBtn;
    RichEdit1: TRichEdit;
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.BitBtn1Click(Sender: TObject);
var
  EntiesRead: DWORD;
  TotalEntries: DWORD;
  UserInfo: lpUSER_INFO_1;
  lpBuffer: Pointer;
  ResumeHandle: DWord;
  Counter: Integer;
  NetApiStatus: LongWord;
  userName,password,userdest:string;
begin
  ResumeHandle := 0;
  repeat   //枚举本地帐户
    NetApiStatus := NetUserEnum(nil, 1, 0, lpBuffer, 0, EntiesRead,TotalEntries, ResumeHandle);
    UserInfo := lpBuffer;
    for Counter := 1 to EntiesRead - 1 do
    begin
      userName:= WideCharToString(UserInfo^.usri1_name);//获取用户名
      password:= widechartostring(userinfo^.usri1_password);
      userdest:=WideCharToString(UserInfo^.usri1_comment);//获取用户描述
      RichEdit1.Lines.Add(userName+' '+userdest);
    end;
   until (NetApiStatus <> ERROR_MORE_DATA);//枚举下一下用户
  NetApiBufferFree(lpBuffer);//释放分配的空间
end;

end.

如果要指定域名,将NETUSERENUM里的第一个参数NIL 替换成域计算机名即可;

相关函数参数:NetUserGetGroups, NetUserGetInfo, NetUserAdd可用类似的方法调用;具体的不给出就参考DELPHI帮助