If he is a "n00bz" then he probably got his anti-virus with his PC and it should be trusted.
Even if it was the anti-virus that did it, I doubt that it can make his PC "Pop".
I'd bring it into a shop, I know that "n00bz" like him are hard to work with, even more when we don't have a direct way of talking to him.
If your friend is willing to, try turning it on again. Keep a camera nearby in case of a bluescreen or anything else like that. check if the fans are working, a loud noise prob means that something happened to a moving part, such as his hard drive or fans.
Best of luck.
-Graboy