Issue 1 – Sync Hardware Clock
At certain parts of the day the PC will try to sync the clock and in turn wake the computer up. Go to Control Panel > Hardware and Sound > Power Options > Change plan settings > Change advanced power settings > Sleep > allow wake Timers which you will disable.
Issue 2 – Network adapter
This can be caused from other computers in your local network or from something remote. Go to Device Manager > Network adapters > name of your Controller (Realtek … Family Controller) > Power Management > Allow this device to wake the computer is to be disabled.
In my case these were the solutions that brought a stop to the random waking up of my computer. Other issues could be problematic peripherals like the mouse, keyboard or any other device. In that case just disable those devices from being able to wake the computer up from the Device Manager and following the same logic of the solution of Issue 2.
Then you’d ask about how to wake up the PC if both keyboard and mouse are disabled from being able to do that. Well, while the computer is asleep just press the power button and it will wake up! Pretty cool, eh?