Make sure System Restore is disabled
Open Regedit, search for these keys and then delete them in Safe Mode
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\AntiVirusDisableNotify (Disabled.SecurityCenter)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\UpdatesDisableNotify (Disabled.SecurityCenter)
Open Regedit, search for these keys and then delete them in Safe Mode
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\AntiVirusDisableNotify (Disabled.SecurityCenter)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center\UpdatesDisableNotify (Disabled.SecurityCenter)