Solved Why does my PC self-wake up?

I recently replaced my system's USB cabled mouse and trackball with a wireless Bluetooth lighted keyboard and wireless trackball. Everything is working OK - except the system wakes up by itself after I put it to sleep. Needless to say it did not do that when the 2 devices were wired ones.

So - what do I have to do to stop the system from waking itself up? Here's my typical scenario that starts with everything powered off

Power on PC
While it is booting I turn on the trackball and keyboard - they both have their own on/off switches
The system runs A-OK until I want to leave it for more than a half hour or so (sometime up to 6 -8 hours)
I use the Sleep command to put the system to sleep
I turn both the trackball and keyboard off
The system sleeps, both monitors show black screens, and I walk away
When I come back my 2 monitors are on and the PC is running

Something is causing it to wake up - but what could it be: I turned "wake on LAN" off years ago, so that should not be it. I've checked the on/off switches on both devices and they seem to work ok.

You can disable "allow this device to wake the computer". In device manager, you can expand the mouse section, and then right click on the mouse. now, click on properties and go to the power management section. untick the "allow this device to wake the computer".


Do the same for the keyboard as well.

Now, you can pinpoint the issue, if its actually cause by the mouse and keyboard (probably is) or something else. If it now stops happening, you can leave it this way till you find a solution, and till then, you can wake the computer from the power button.

You can see what woke your computer last by opening command prompt as administrator and typing powercfg -lastwake

Excellent suggestions - thanks. Now that I see it again I remember the lastwake trick - I had completely forgotten it. Will try not to do that again.

The Lastwake trick was the key to fixing this problem. It showed that my Ethernet controller was the cause of the last wake, and I found that the last 2 wake option were enabled. so I switched them to disabled. Problem solved.