貌似僅限於ie，且有許可權問題。

<script   language=javascript>   
  var   WshShell   =new   ActiveXObject("WScript.Shell");   
  alert("計算機名   =   "+   WshShell.ExpandEnvironmentStrings("%COMPUTERNAME%"));   
  alert("登入使用者名稱   =   "+   WshShell.ExpandEnvironmentStrings("%USERNAME%"));   
  </script>   
    
  <script   language=javascript>   
  var   wshNetwork   =   new   ActiveXObject("WScript.Network");   
  alert("域名               =   "+   wshNetwork.UserDomain);   
  alert("計算機名       =   "+   wshNetwork.ComputerName);   
  alert("登入使用者名稱   =   "+   wshNetwork.UserName);   
  </script>