Remove security option from Start menu (Terminal Services only)
Computer Configuration\Administrative Templates\System
Removes the Windows Security item from the Settings menu on a Terminal Services client.
If you enable this policy, the Windows Security item does not appear in Settings menu on the Start menu. As a result, users must type a security attention sequence, such as CTRL+ALT+END, to open the Windows Security dialog box on a Terminal Services client.
This policy is designed to prevent inexperienced users from logging on to Terminal Services inadvertently.