Computer help forum: My laptop freezes after only a few seconds. What do I do?

Hi,
I don't have all my system info just now as I am having to use a library computer and didn't bring my laptop, but it is an HP with Windows 7. I purchased it in August of 2010. I use Norton ... security suite, or something along those lines.

And first off, this may not be related to the problem at hand, but I've had an ongoing issue with my computer trying to do an update when I shut it down every now and then, and it will be stuck on "Update 1 of 1" for such a long period with no sign of progress that I usually have to force close as I don't have time to wait and see that it completes, and because I don't want it stuck on the screen while I'm away for hours as it has done before.

But that whole issue has only ever been a minor annoyance, so I don't know if it is related to what happened today. The reason I bring it up is because that is circumstance under which I had to shut my computer down last night before going to bed.

When I woke up this morning, I turn on my laptop, logged in, and left to shower. I came back about 20 minutes later and found that it was off. I turned it on again and got the message that the computer had overheated. This is the first time that has ever happened.

So I continued to the log on screen and went about it all like normal, but when my desktop came up and I sat waiting for it to finish doing all its start-up loading, I went to move the mouse after about 15-20 seconds and found it frozen. Everything was frozen; I couldn't even ctrl-alt-del. So I had to force close.

This exact situation has happened every time I've tried to use my computer today, minus the over-heating message. It even happens in Safe Mode, so basically I have zero use of my laptop right now.

I have no idea where to begin trying to fix it since I can't access my files or anything on the computer with it freezing like this.

What am I supposed to do?