Administrative Templates\System\Group Policy
By default, computer and user Group Policy is updated in the background every 90 minutes, with a random offset of 0 to 30 minutes. In addition to background updates,
Group Policy for the computer is always updated when the system starts.
Group Policy for users is always updated when they log on.
You can specify an update rate from 0 to 64,800 minutes (45 days). If you select 0 minutes, the computer tries to update user Group Policy every 7 seconds. However, because updates might interfere with users’ work and increase network traffic, very short update intervals are not appropriate for most installations.
If the Disable background refresh of Group Policy policy is enabled, this policy is ignored.