It’s extremely annoying when a computer that you know you did set to sleep suddenly wakes up on it’s own. And for some reason it always seem to do it in the middle of the night! So how do we fix this problem?
Start cmd and run this command: powercfg lastwake
That might give you some info about what application that is forcing your PC to wake up. However, if you’re unable to find the reason there’s other ways around this problem.
Step 1: Check the if the “Automatic Maintenance” is set to wake up the computer and also change the time to a time that fits your schedule better.
If you type “Automatic Maintenance” you should be able to find the settings. (This may vary because of Windows versions, just look around, you’ll find it.)
Step 2: Open up the “Task scheduler” from the start menu. Check all the scheduled tasks and change the time or disable the tasks if you don’t need them to run.
Step 3: Some computers doesn’t have this option. Open up “Power policy” go to “Advanced settings” then “Sleep” and then “Allow wake timers” and disable that if it’s active.
That’s pretty much all you can do about this as far as I know, hopefully it will solve your problem. Good luck!