You'll need to be in the admin account, or yours must have admin privileges. In regedit, navigate to [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Applets\Regedit] and look for the value LastKey. Double-click it and clear the string. Then right-click the Regedit key (in the left-hand pane) and select Permissions. Set Permissions to Deny for any/all users/group. IMPORTANT DISCLAIMER: Before doing anything with registry, It is very important that you take a backup of registry by exporting it. Remember even a minor mistake in registry could render your system unusable or will cause it to stop or crash. XPTOOLS is not responsible for any such damage that may occur directly or indirectly as a result of your applying these changes. Don't try it if you are not sure. Use at your own risk