Laptop Restarting?? No Idea what's happening

Heya,

My brother has a Alien Ware Area 51 Win Vista laptop - one day it would go to the login screen and restart within seconds... kept doing this over and over again

We pressed F8 and out of all the options, the ONLY one that does not restart at login screen is "Reboot at last good-known setting (Advanced)"

-We checked for spyware - nothing
-We also went to My Computer and "right-clicked" on the C drive and clicked on Tools ---> Error Checking ----> Check Now ---> Reboot and waited for the computer to check for errors ---> Nothing

So it's not any of them... hmmm we did not do a virus scan 'cause we have no program for it (any recommendations?)... eitherway he does not remember if he went on the Internet or not before it started rebooting

It could be software, hardware or a virus issue... not sure where to start... any ideas? Alienware customer service just said "format your computer over again" - the easy way out

Most amazing jew boots

Nope no updates - just goes to the login screen and within seconds boom

@Zergrinch what do you mean by event logs?

@Sol I'll run both scans and thanks

There's nowhere I can't reach.

K got the logs - used winrar to add both to the same folder

Thanks

This thing is sticky, and I don't like it. I don't appreciate it.