I've been having issues with my Toshiba laptop. I bought it about 3 years ago. It shuts off without warning when I try to do a virus scan. Also when I've tried to down load an antivirus program off of the net. I erased the crappy AVG antivirus program and got a copy of Norton 2003. I downloaded the updates without a problem. But it shuts down about 8-10 minutes into the scan. The scans that I have done have not found anything. I've manually scanned some folders and have found nothing. The power cord is plugged in while I'm doing this. Since it shuts down without warning could it be a harware issue? Any help is appreciated.