My Windows 7 laptop and Windows 8 Surface Pro kept waking up from sleep while in my bag and causing it to heat up and drain the battery. So I ran the following command in command prompt:
powercfg /lastwake
This told me the last device that woke my laptop up, it was wuauserv. Windows Update. Change Windows Update to anything but Automatically download and install updates. I changed mine to manually install.
If nothing shows up from running the command above then have a look at other devices that might be set as an option to wake up the computer.
Running the following command will show which devices are set to “Allow this device to wake the computer”
powercfg -devicequery wake_armed
Un-tick the the “Allow this device to wake the computer” box for for devices shown above in device manager.
![device_manager[1]](https://marckean.files.wordpress.com/2013/06/device_manager1.jpg "device_manager[1]")
Marc Kean 
Thanks for this. My first search didn’t find your post but just searching for ‘lastwake wuauserv’ did. I thought I already had update running on a notify only basis but was wrong about that. Now it is. In my case it involves a desktop but I still don’t want it running all night after 3AM. Pretty poor that the machine doesn’t go back to sleep after checking for updates. I thought this type of stuff was supposed to be all ‘fixed’ with W7. Oh well :)
Hi! Do you use Twitter? I’d like to follow you if that would be okay.
I’m definitely enjoying your blog and look forward to new updates.