I recently ran into a little problem, since i've had my computer i've run mcaffee antivirus, and all was good, but every so often i would put my laptop into hibernate (usually to pause it so i could put it away and travel to my next class.) sometimes on bringing it out of hibernation i would be greeted with a message saying
"MCSHIELD.EXE has encountered a problem and needs to close"
every such instance of this forced my computer to crash completely, to the point the only way to get it working was hold down the power button until it shut off.
so after having been fet up enough of this, I decided since i was headed to hardware services to buy some dvds, i would stop by at the help desk (which is right before the hardware sevices ) to find out why it was doing this.
The person asked me what was wrong, and i explained ( exactly what i had said above. )
The guy then opened my mcaffee and looked through the error logs, and noted all the instances this had happened, then he noticed that the dat files were corrupted, ( the dat files give the antivirus the ability to identify what is a virus and how to remove it. ) so he repaired the antiviurs with the repair tool, and then updated the antivirus. so now everything should be in working order.

but the thing is for the last i dunno ( maybe since i got it ) i've had no antivirus protection, the program was working but the files were corrupted, so it could run scans and diagnostics but it couldn't identify a virus to save my laptop.

the moral is: check to ensure your antivirus is updating and working properly and isn't corrupted by looking at the error logs, also get familiar with the error logs so you have a general idea whats going on with your pc.

I do that,my virus protection auto scans once a week,and takes half an hour to do that,and I update it everyday or so,when there's a update.

My antivirus protection scans 24 hours non-stop.

My anti-virus automatically updates. Plus I have it set to scan the computer at least once a day, usually during the hours I'm at school. Sometimes my brother shuts off the anti-virus though which pisses me off.

I have two anti virus programs from the same company (It's got an ability to ignore other antivirus programs so its ok.) So I've got a system of checks and ballances so I'm ok I guess,