My computer turned on by itself, how is that possible?

Question

I have WinXP Pro, one night I got up and noticed it was on, at the "Disc Cleanup" window. It takes 3 clicks on the mouse to get there. Do I have a "Hacker"

Answer 1

Probably not a hacker. Today's computers go into a "sleep" state at power down (if you look inside the case, a little light will be on). The BIOS can start the computer automatically at specified times.

Answer 2

strange? better turn off your pc at night, most esp your internet connection- just for precaution:)

the "disc cleanup" must have been programmed to auto-run at certain time of day - you may need to change the setting.