W7 wakeup debugging

[The late XV105]

It has been an age since I last posted here!
Some help, please.

My home-built PC runs Windows 7 x64 Professional and usage includes Media Center. Because of this I routinely use sleep instead of power off so that it can wake up, record a Freeview show or download the latest guide listing, and go back to sleep. This has worked faultlessly since build several years ago until the last couple of weeks when the PC started waking up within five minutes of being put to sleep.

I started to investigate by using the Command window and looking for devices enabled to wake the PC:

C: \Windows\system32>powercfg -devicequery wake_armed
eHome Infrared Receiver (USBCIR)

This is fine and confirms that the only device configured to wake the PC is the Media Centre IR receiver; nothing has been enabled that was previously disabled (via power management options in the Device Manager). Just to be sure I removed the IR receiver and the ethernet cable (in case magic packet related) and put the PC back to sleep. It woke up within five minutes - so the problem must be a wake timer. Time to see what I have:

C: \Windows\system32>powercfg -waketimers
There are no active wake timers in the system.

Hmmm - so I tried this:

C: \Windows\system32>powercfg -lastwake
Wake History Count - 1
Wake History [0]
Wake Source Count - 0

Very helpful! :(


I have spent hours carefully going through the scheduled task list as well as one-by-one disabling possible software sources such as antivirus live update - all without finding the source.

If I disable wake timers in Advanced Power Options the PC stays asleep (of course) but I don't want to do this because I can't then use it as described in the opening sentence.

How to get to the bottom of this, please?
Any utilities I can try?

As well as simply not wanting to be beaten the thought crossed my mind of a Nasty trying to phone home.

TVM,
105

[Avtrician]

does the wake up occur at the same time every day?? if so, it could be a lighting control signal being sent down the power line.

Check the bios settings, wake on lan could be set.

[The late XV105]

Thanks for the thoughts, Avtrician but as mentioned in my original post, wakeup happens every few minutes as opposed to the same time (once) every day. To be precise, almost exactly every five minutes to within a fraction of a second according to the log files.

Also per my original post, even with the the Ethernet cable removed the PC still wakes up after a few minutes asleep. There is no WLAN or other means of network connection with the outside world. Magic packets or anything else network-related is therefore ruled out on top of the fact that everything to do with this is disabled anyway in the BIOS and in W7.

Until recently, sleep and wakeup behaved perfectly; sleep after 30 minutes of inactivity (which is still the case) and wakeup either for Windows Update at 3:00am or Media Center TV recording or guide download. I have not changed any settings or installed any new software in a long time - so the problem appears either to be related to an update (Windows or application software) or the PC is infected with something that I can't find; I have done a lot of digging, including as far as root kit detection.

[The late XV105]

Gave up. Restored to System Image of two weeks ago. Problem gone.