For the last few weeks my personal Windows PC has been waking up seemingly at random from sleep. The computer will then go back to sleep after around 15 minutes thanks to my power settings. The computer then gets woken up again. I’ve turned off my wireless mouse and unplugged other peripherals to ensure there was no external input. I even closed all apps to ensure nothing was running to wake it up.
So I got Googling. And I found a command I’d not seen before:
powercfg /lastwakeThis command shows the reason for the last wake of the machine.
Running that in Command Prompt gave me this:
Owner Supplied Reason:
Windows will execute 'NT TASK\HP\HP Print Scan Doctor\Printer Health Monitor' scheduled task that requested waking the computer.Okay, I’ve found the culprit. HP Print Scan Doctor – Printer Health Monitor. Ok that makes sense, I just got a new printer last month. I have the printer software installed and its added a Scheduled Task as part of the install.
After kicking myself for not thinking of this before, I take a look in the Task Scheduler app.
And here’s Printer Health Monitor (which I’ve now disabled) with multiple triggers and ‘Wake the computer to run this task’ enabled.
This trigger schedule is absolute madness. HP have decided that every 1 hour for the next 15 years(!!!) my computer should wake up and check for a software update. A staggering decision. And likely something not just HP are doing.
Now I’ve disabled this the problem has stopped. But it does beg the question just how many machines are doing this? How many printer and other vendors are using task scheduler to wake up likely millions of devices just to check for a new software update? Surely Microsoft should have some controls in place around who can use this functionality and for what purpose? The amount of potential energy wasted is staggering.
Anyway, hopefully this helps a few people out there with fixing a frustrating issue, and saving a little on their energy bill at the same time!