The computer shutdown would have stopped the scan, I suggest you run off direct power whenever possible when running security scans.
This item: Security Center\FirewallDisableNotify (Disabled.SecurityCenter)
is explained here: http://www.safer-networking.org/en/faq/46.html
Additional info: http://www.safer-networking.org/en/faq/index.html
http://www.safer-networking.org/en/tutorial/index.html
Update then scan with SAS and post the results.
Update then scan with Symantec AntiVirus and post the results.
Thanks