My laptop was having random shutdowns. here is the topic
http://www.staredit.net/topic/4203/
I sent it back to dell and they fixed it. They replaced my motherboard and my heat sink.
So maybe I overheated it..?

My laptop does this all the time. I am a vista user, if you think that matters. I set it on my lap, my desk, all sorts of areas. On my desk if I leave it on for about 6 hours then it will get really warm, but not skin burning warm (although sometimes it is very close). If I set it on my lap, it will heat up a bit faster, although I myself have never had it shut-down from overheating both if I have it on my lap or not. Laptop stands will only matter for heating if you are doing something that produces a lot of heat, or like to keep your computer parts nice and cold. So any other questions?

I'd honestly go for one of the Laptop coolers that you can set your laptop on.. I work at Staples and a lot of people have said good things about them when they come in for other things.