I got rid of that PC a year ago :P But trust me, I tried literally every trick in the book, including the one above. No devices had the capability to wake up the PC(yes, including the mouse and the keyboard), disabled all wake timers, disabled all networking(in fact unplugged the ethernet cable).....it would still wake up in the middle of the night. It was the most confusing thing I ever dealt with in computers.

Was this exactly at midnight, as in 12:00?

It's possible auto wakeup was enabled in the BIOS, with the wake time set to the default of 00:00.

Alternatively, if it was a different time, perhaps *that* was the default, or maybe the value accidentally got changed.

Alternatively-alternatively, maybe the BIOS had a bug in it that somehow enabled auto wake without presenting an option. To tackle this, I would've reset the BIOS settings. (I once had an ADSL2+ modem that randomly started flaking out and not connecting correctly. Changed every accessible setting I could, no dice. Factory reset = instantly back to normal.)

yeah, software can wake the PC too. alarms and the like will wake a sleeping PC.

in your case I would scrutinize the task scheduler for tasks that are allowed to wake the PC.

I wish I had known about this.

That said, the tablet felt so infuriating to me that I was honestly happy when it was gone again, despite the financial loss.