I have a sony laptop running XP. I was browsing and suddenly it just froze up. I tried to end task, then I just shut it down. Now it will not do anything. When I turn it on, the lights turn on, and a little fan spins for a sec, the nothing else... at all. I can't even get to any bios or anything.

If the bios is not showing up it migh tbe a CPU (processor) problem. I've turned a computer on after changing the heatsink on a CPU once when I actually forgot to put the CPU back in, and it did about the same thing. If you can get another one that will fit in the socket, try testing it with that.