Computer Restarts for No Reason

Hi All,

I have a Toshiba Satellite running Windows Vista. This has been a great computer. I've used it for YEARS without any hiccups whatsoever.

All of the sudden, however, the computer randomly shuts down when I'm in the middle of using it and reboots. When it reboots, I get the message that an improper shutdown occurred, and I'm given the option to start in safe mode.

I have turned off "Automatic Shutdown" (or whatever the option is), and I don't think it's a power problem, as the computer is almost always plugged in when I'm using it.

I found a similar thread on the forum that is closed: http://forums.techguy.org/windows-vi...ndomly-no.html

My question is how do I test to see what's going on with this computer? I can't afford another one right now, so I really need to figure this out. FYI, I'm not tech savvy, so I'll need people to be patient with me as I work through your solutions.

Thanks everyone!