My computer will automatically shut off sometimes, I need help to solve the problem!?

My laptop instantly dies, I don't think it's the battery because it's always plugged in when I'm using it and I've been taking it out since it started doing this when I'm not using it. I gotta get it to stop though, I'd be very pissed if I'm writing a long paper at college and the damn laptop kills itself on me.
 
The battery is working perfectly fine for me, otherwise it wouldn
't ever turn back on. It also has a greenlight on my laptop representing the battery is workng fine.
 
You can't put a laptop on a couch. It will overheat and automatically shut off to keep it from overheating to the point where hardware can melt or be otherwise damaged. Place it on a surface that's not a good heat conductor, and prop up the back so that heat can escape better. You may also have problems with the fan, so check for airflow.
 
Polar-BlueScreenOfDeath.jpg

The blue screen of death!!!! Windows doesn't do that anymore. They completely took the blue screen of death away.
 
Turn on a fan beside it and leave it on top of a desk for a few days so it can cool down.
Btw, Windows>Macs cause macs suck (my windows xp lags a lot [but it might just be this site], but at least it's still 999999 times faster than the new macs at my school).
 
AMD Athalon 64 Processor
2.06 Gigahertz, 2 gigs of ram.
250 gig hardrive
Killer video card

It's probably none of that except for the harddrive.

I pull the power chord when I get pissed off.
 
i get that blue screen that says irql not less or equal or whatever after running soulseek for a couple hours or just randomly at any time after i've turned soulseek on anytime and i have to restart my computer. it could happen from 5 minutes after i turn it on to 5 hours after i turn it on and even sometimes after i've shut the program down. does anyone know what could possibly be wrong?