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Periodic Refresh Processing.
Group Policy is processed periodically. By default, this is done every 90 minutes with a randomized offset of up to 30 minutes. You can change these default values by using a Group Policy setting in Administrative Templates. Setting the value to zero minutes causes the refresh rate to be set to seven seconds.

Setting a short refresh interval in a production environment is not recommended. This is because a policy refresh causes the Windows shell to be refreshed, which in turn causes all open shortcut menus to close, a brief flicker of the screen, and so on. In addition, it causes computers to contact domain controllers more frequently, increasing the load on the domain controllers. However, setting a shorter interval may be useful in test or demonstration scenarios.

To change the policy refresh interval setting, edit the Default Domain Controllers Group Policy object, which is linked to the Domain Controllers organizational unit. The Group Policy Refresh Interval for Computers setting is located under Computer Configuration\Administrative Templates\System\Group Policy node.

For domain controllers, the default period is every five minutes. Group Policy Refresh Interval for Domain Controllers setting is available under Computer Configuration\Administrative Templates\System\Group Policy node.
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