pc mystery

[powyco]

I have always shut my PC down in the correct way, but recently it has switched itself on several times. I have checked very carefully that it really is off. Yesterday I was in the room, heard a clicking noise from the tower, and it switched on again, after being off all night. How is this possible ?

[evenstar]

I don't know why but my pc does this too sometimes! I have a power switch at the back of my pc so after shutting my pc down I turn it off with the switch at the back as well, this sorted it for me - I just had to remember to switch it back on!

[powyco]

I'm trying to remember to switch off at the mains, too, evenstar. Let's hope someone comes up with an explanation of what these mad computers are doing!

[rojash]

One possible cause is a brownout on the mains. Most PCs have a setting in the BIOS which allows you to dictate the behaviour in case of restored power. The usual settings are On, Off, and Remember last State. If you have it to set to ON, then after a blackout or brownout, the machine will switch on automatically.

[Ralph]

While you're checking the BIOS for what rojash talks about, also check that Wake On LAN and/or Wake On Modem (or wake on call maybe?) are set to Off as well.

These might cause the PC to boot when it receives a signal via the modem cable or the network cable.

[powyco]

Thanks rojash and Ralph. Your advice much appreciated.I don't know enough to check as you suggest, but I'll ask the man who fixes problems for me. I wonder now if it could have been caused by a violent thunderstorm we had here about three weeks ago. My computer, and others in the village, were knocked out, in spite of me having a circuit breaker.