Computer Starts-Up By Its Self

[JCO]

Running Windows-XP Professional with all updates including SP3 & IE7
Motherboard: GA-MA78GPM-DS2H

My Computer starts up all by its self. I don't think it starts at the same
time each day... seems to be random. I've been looking in my BIOS, but I
can find a section that indicates a startup. I know some computers have
this feature turned on but I don't. What else can cause this? Most of the
time, I wake up in the mornings and my computer is on. Today, it was not
on, however, I heard it boot up at 11:45 AM (Mon 11/3/08).

Can someone give me some clues? I built the system myself so I'm familiar
with all the hardware.

Thanks in advance.

 

[Leonard Grey]

Is the system powered off when this happens?

If yes - someone is turning your computer on.

If no - is wake-on-LAN enabled?

 

[JCO]

System is powered off but the switch on the back is still on.
No body is powering it on. Today's event happened just before noon. I was
the only person in the house today and at 11:45 AM, I heard my computer boot
up (the music played).

 

[Ken Blake]

System is powered off but the switch on the back is still on.
No body is powering it on. Today's event happened just before noon. I
was the only person in the house today and at 11:45 AM, I heard my
computer boot up (the music played).

Go to your BIOS. Look for and turn off any "Wake on..." settings.

 

[JCO]

In the power management (of BIOS), I disabled the following:
PME Event Wake Up
USB Wake Up
HPET Support (High Precision Event Timer)

The manual does not explain any of these feature in detail enough to
understand what they do. However, I think the issue is resolved.

Thanks

 

[JCO]

Sorry, the USB wake Up is suppose to read:
USB Wake UP form S3

Still don't have a clue as to what S3 means.

 

[Swifty]

In the power management (of BIOS), I disabled the following:
PME Event Wake Up
USB Wake Up
HPET Support (High Precision Event Timer)

In my opinion it probably wasn't HPET (about which I knew nothing, then
I read the Wikipedia page, so now I'm amongst the most knowledgeable
people on the planet. Well, in the top million or so.

With HPET disabled, be on the lookout for games that don't flow so
smoothly, and audio or video "jumpiness".

 

[David B.]

Google can fix that.

http://en.wikipedia.org/wiki/Advanced_Configuration_and_Power_Interface

 

[JCO]

The problem is resolved.
But I think I will go back and turn HPET to enable..... based on what you
said earlier.