Laptop

Hello,

I recently came to acquire a laptop I knew has had some trouble, it wouldn't boot. When the power button was pressed the power light in front of the laptop lit up for a second (as if beginning to boot) and then went off again slowly. No other signs of power, no fans, no beeps, nothing. This would happen with the battery in, battery and connected to power supply, and when it just has the power cord connected. Just another small note, the laptop still recognizes when the battery is being charged.
A few months ago I took the whole laptop apart to see if there was any visable sign of something wrong with the MoBo and there was nothing that I could tell. So I put it all back together and forgot about it. Well a few nights ago, just to see what the "symptom" of the laptop was to research some more, I plugged it in and pressed the power button to remember what happens, but this time it booted. It went all the way to the windows loading screen and stayed there awhile until it bluescreened and said "IRQL_NOT_LESS_OR_EQUAL". It then ran a process to "resolve" the issue. It could not resolve it and the laptop went to restart only it never came back on. It went back to the symptom of the single light turning on slowly then turning of slowly.
I am asking for any idea as to what is up with the laptop. ANother note, when it was at the windows loading screen, there was not actual logo for windows, just the loading bar. It says it runs vista on it (I wouldn't know that for a fact since I never seen it actually load, the previous owner is no longer around) Here is a link to the specs, any ideas are welcome.
Thank you

http://support.gateway.com/s/PC/R/1008835/1008835sp3.shtml