Does the user running the script have permission to create keys within HKEY_CURRENT_USER/Software/Policies/Microsoft/Internet Explorer/Restrictions? On XP, if I log in as a user which has such permission (as determined by using regedit to create the keys directly), then the script successfully creates the keys, but if I log in as another user with insufficient permission to create such keys using regedit, then the script fails with the access denied error.