My PC starts by itself

[esha]

I've got a new PC, Win7 Professional came pre-installed.

Now it's the second time that it has started itself while I was away. I hadn't even known that was possible!

Could that be the effect of some malware?
How can I find out what the stupid thing has been doing while it was active without me?

 

[Brink]

Hello Esha,

Oh yes, there's several things that can wake up your computer to do whatever task.

You might check your wake source log in Event Viewer to see if it may reveal what is waking up your computer.

http://www.sevenforums.com/tutorials/179257-wake-source-read-event-viewer-log.html

Hope this helps for now,
Shawn

 

[Layback Bear]

Yes malware can cause this. It could be calling home. If your computer is set to sleep and a auto update kicks in could also cause it. I know of no way a program can do a cold boot. (Computer OFF)
The first place I would look is Windows Updates and see if it set to auto check for Updates. Then I would check if your anti virus is set to auto update.
If you are concerned with infection I would do this in this order.
1. Run a updated full scan with your anti virus.
2. Run a updated full scan with MAM
3. Run a updated full scan with Eset
---------------------------------------------
Malwarebytes

Free Online Virus Scanner | ESET
-----------------------------
Sorry I'm slow.

 

[OvenMaster]

Check all your BIOS settings thoroughly. Some - like my ASRock does in "Advanced Chipset Configuration" - have "alarm" type settings that will boot the rig up if activated.

"RTC Alarm Power On
Use this item to enable or disable RTC (Real Time Clock) to power on the system."

 

[DocBrown]

There are some other Bios settings, too. ReStart computer after electrical power failure, wake on modem ring, wake on Lan, etc. These can be turned ON or OFF in the Bios setup.