Auto Shutdown

I should start by saying that this is my first time trying to repair my own electronic device but I have all relevant tools and am wanting to learn. Money is tight right now but time is abundant. I have already been in contact with Sanyo's repair line and, needless to say, they weren't any help...

Few days ago, I accidentally downloaded some Malware and Trojan Horse stuff. I deleted it soon afterwards, and reactivated AVG, which was turned off. After few days, my Laptop auto shutdowned without warning or anything, I noticed that it was timed, It always shutdowned after every 2 Hours...