My subscription to Norton recently ran out, and I'm switching to Spybot and AVG. I've been a couple of days with no protection and have been online.
I get the "include file" errors several times during a Spybot scan, even though I have repeatedly updated the definitions. The list of file types I get the message about is:
HeavyDuty.sbi
Hijackers.sbi
KeyloggersC.sbi
Malware.sbi
MalwareC.sbi
Trojans.sbi
TrojansC.sbi
That's a lot of potential problems!
I also got the errors "MicrosoftWindowsSecurityCenter_disabled" and "Microsoft.Windows.Active.Desktop"