In tip 2492, I describe filtering Local Group Policy.
Some Group Policy settings take place immediately, before you have finished configuring and filtering.
To prevent this behavior, Enable the Disable background refresh of Group Policy policy at Computer Configuration \ Administrative Templates \ System \ Group Policy.
The Explain tab contains:
Prevents Group Policy from being updated while the computer is in use. This policy applies to Group Policies for computers, users, and domain controllers.
If you enable this policy, the system waits until the current user logs off the system before updating the computer and user policies.
If you disable this policy, updates can be applied while users are working. The frequency of updates is determined by the "Group Policy refresh interval for computers" and "Group Policy refresh interval for users" policies.
NOTE: See Windows 2000 Group Policy refresh.