This policy setting determines when security policies are updated.This policy setting affects all policies that use the security component of Group Policy such as those in Windows Settings\Security Settings.This policy setting overrides customized settings that the program implementing the security policy set when it was installed.If you enable this policy setting you can use the check boxes provided to change the options. If you disable or do not configure this policy setting it has no effect on the system.The "Do not apply during periodic background processing" option prevents the system from updating affected policies in the background while the computer is in use. When background updates are disabled policy changes will not take effect until the next user logon or system restart.The "Process even if the Group Policy objects have not changed" option updates and reapplies the policies even if the policies have not changed. Many policy implementations specify that they be updated only when changed. However you might want to update unchanged policies such as reapplying a desired policy setting in case a user has changed it.