That'll do actually. Unless something else comes up. We'll just have to see if after cleaning and scanning for viruses will resolve the rebooting issue.
AVG is good. In my opinion I like Microsoft Security Essentials (MSE) better because it's not as much of a resource hog and it's more simple and user friendly.
Probably not, but it's a possible cause to his computer restarting by itself, if it was too high.
I only told him to disable auto-reboot so if it was a case of BSOD we can isolate the problem better, instead of having the computer restarting by itself.