I have a weird problem with my laptop. It's a 3-4 year old Dell Inspiron 8500. Basically, when I turn it on, it boots fine, loads up XP pro, I can login and work on it for 1-2 minutes. After 1-2 minutes, the display slowly starts to decay (these colored dots start appearing on the screen, the screen starts flashing every few seconds, and then it just basically freezes). This also happens if I boot into the bios menu and let it sit for a couple of minutes (so it's not a hard drive problem). If I try to restart it immediately after this, I just get a screen with a flashing cursor (sometimes this screen has these very odd lines running from top to bottom and left to right on it) and nothing happens. I have to let it sit for at least 15 minutes before trying again, after which it boots fine as before and the problem starts all over again.
I'm thinking either motherboard, or graphics card, maybe the lcd screen. It's out of warranty, so I'm probably not going to pay to replace parts on such an old computer, but I thought I'd see if anyone has any other ideas.
Thanks in advance,