/**
 * Remove all files and folders that are older than a set number of days.
 *
 * @param rootURI The URI of the root folder. All old files and folders in this
 *                folder are removed.
 * @param days Files older than this number of days are deleted
 */
function purgeFiles(rootURI, days) {

  var fso = new ActiveXObject("Scripting.FileSystemObject");
  var rootFolder = fso.GetFolder(rootURI);
  var subFolders = new Enumerator(rootFolder.SubFolders);

  // create a date before which files are considered "old"
  var threshold_date = new Date();
  threshold_date.setDate(threshold_date.getDate()-days);

  // loop over each file
  subFolders.moveFirst();
  for(;!subFolders.atEnd(); subFolders.moveNext()){
     var f = subFolders.item();
     if(f.DateCreated < threshold_date ){
        //WScript.Echo("Deleting "+f.Name+"  last accessed on: "+f.DateCreated);
        f.Delete(true);
     }
  }

}

purgeFiles("C:/path/to/folder", 300);