My PC mysteriously turn itself back on

hi....got another problem here...recently my pc began to mysteriously turn itself back on after I turn it off....I checked if my pc got a trojan, or virus through my anti-virus which I always update and even downloaded a spybot to see if there are any spywares, my anti-virus and spybot didnt find any so i asked a friend of mine to check on the BIOS setting, and he said everything is just ok...I already replaced my power supply and its still the same....what could be the cause of the problem....

btw, my motherboard is AMD and I dont have those WOL(wake-on-lan) thingy...

thanks a bunch!!

Try resetting your CMOS.

Turn off the machine and unplug the PSU.
On the motherboard there should be a 3 pin header for the CMOS with a jumper spanning 2 pins.
Lift the jumper off the 2 pins and move it along 1 pin to short it out.After a few seconds put the jumper back into its original position.

if the pins are theoretically numbered 1 ,2 ,3 the jumper will be on 1 & 2 . Remove the jumper and re-position it onto 2 & 3. After a few seconds put the jumper back into its original position.

OR if you cant find the jumper to RESET the cmos try taking the steps rev suggested but instead of the jumpers find the battery that looks like a watch battery and take that out for about 2-3 mins.

Just my two cents......

Some trojans weren't detected by Nortons for me. I use a program called Trojan Hunter version 3.8 is now available. It catches them, cleans them and it is NOT a memory hog!

Sharon

The Reverend should have fixed this problem by resetting the CMOS, however certain PC's have a feature to auto turn on the pc.Check your BIOS again for anything like this and turn it off.Mine has this feature and it drove me crazy untill I figured out why my system kept turning on in the middle of the night.Just a thought..Does this problem occur if you force the system to shut down?By holding the power button for several seconds...

Yup, I had my BIOS set to turn on at the press of any key on the keyboard. Some keyboards send out a constant signal thus turning the PC back on. I would follow Wolfman's advice first before considering a full RESET.