What are somethings that would cause a computer to randomly reboot? In the computer lab i work in they just do it anytime, just turning on & pooof, in the middle of typing report or just idle with nothing open. I checked some of the boxes and their cpu fans had not worked in who knows how long but all the others that reboot the fans are working. The boxes are kinda cheap athlonxp 1.1 with 512 pc133. PCUSA or what ever mobo's so not the greatest but i wouldn't expect them just to reboot like they are.