starts up by itself

[hydroguy]

I have an old desktop which has recently been reformatted and loaded with Win XP Pro SP3. It has all security patches installed. I don't use this computer, I just keep it around for a backup so I keep it shutdown. But every afternoon it will start up all by itself, it does this as regular as clockwork. It is not connected to my network and has very little software installed. I can't figure out why it starts up itself. Anybody ever seen this or have any clues?

[CLiNT]

Maybe it likes XP so much it needs to run...

Check through and make sure there is nothing set up in the task scheduler for it to run.
Programs; No programs should be alowed to force a computer from a complete off state to an on state.
Go through your bios settings carefully, it'll be hard to tell you what exactly to look for though.

[Deadeye81]

Ron, when you said it starts as regular as clockwork, do you mean it starts at precisely the same time every afternoon?

If not, it could be your motherboard BIOS battery is getting weak and lower voltage is causing the Wake on Lan or Wake on ring in the BIOS to trigger startup even though the PC is not connected to a network. If WOL or WOR are enabled, try disabling them. Also try a new battery.

I am assuming your PC is an ATX form factor, as most have been for several years now. When an ATX machine remains plugged into AC power after shutdown, it continues to draw electricity. That is why we are always told to unplug the computer, not just power it down when we need to look at something inside the case. The BIOS waits for a "power good" signal to be transmitted from the power supply to the motherboard before allowing startup to occur. Something is possibly sending or mimicking a "power good" signal to the motherboard/BIOS to trigger the bootup. Just a thought.

[DaveA]

I think that it is NOT being shut down, but sent to sleep or hibernation and then some scheduled task is waking in up and doing it's thing.

[hydroguy]

Thanks for the suggestions,
I have not setup anything in the task scheduler so I don't think that is the problem.
I don't know if it starts everyday at the same time, I am not always home when it starts up, I just know that it always starts up in the afternoon hours.
It is of the ATX type machine, I will have to check on the WOL and WOR and see if it has that. It could be a weak BIOS battery, since this is a very old machine.

[RussB]

My old DELL Latitude has a BIOS setting to start the computer at a specific time, have you looked for this?

[CLiNT]

Go over your motherboards & BIOS spec carefully, you may have functionality you didn't know you had...

When the computer is powered down but the power supply is still on, it can be started remotely via Wake-on-LAN and Wake-on-Ring or locally via Keyboard Power ON (KBPO) if the motherboard supports it.