Sometimes viruses or people use Group Policy against us and we need to reset it back to the default. It can control access to a number of things in windows from logon scripts to access to the screensaver settings. Resetting it is actually pretty simple, which is why you shouldn’t rely on it solely to guard your network.To reset the local group policy on a machine back to default issue this magical command and after a reboot the GPO settings will be set back to their defaults (enter this all on one line):
secedit /configure /db reset /cfg “c:windowssecuritytemplatessetup security.inf” /overwrite
Also, you should delete the registry.pol file if it exists:
Don’t forget to reboot! All the group policies should now be reset to default.