hey heres what happens. im on my comp and out of the random, it reboots. it doesnt shut down then reboot. it skips that and it brings me to the rebooting window. im running windows XP. the reason IM GUESSING is that its getting too hot and to cool it down it needs to reboot or shut down. i shut it down every nite before i go to bed and keep it shut down until i wake up the next day. or if im away i keep it off until i come back. im not sure how to get into the BIOS little less how to mess with it without having to mess my computer up. i heard that it can be from there but i dont know. my other guess is that it can be shorting out. its a very old computer. i just put in a 120 gigabyte harddrive about acouple months ago cuz i thought that it could be the hardrive that i previously had that was causing it restart. anyway, if theres anyone who wants to help me with this just comment back or email me at firstname.lastname@example.org . i really appreciate this alot.