My Windows 8 PC wakes up every night around 3 am

I just built a new Windows 8 PC, and started using it a few days ago. Every night, I use Hibernate on the computer before I go to bed. The only way to turn it back on is to hit the Power button.

Every night, the computer wakes up from Hibernation around 3 am. Here's the past four days, from when I first started using the computer:

1. Started using the computer.
2. Was using the computer at 3 am, so didn't notice any wake-from-sleep problems.
3. Computer wakes from Hibernation at 2:59:43 am, according to the Event Viewer.
4. Again, the computer wakes from Hibernation at exactly 2:59:43 am.

In the Event Viewer, there are a few relevant events, but none that really specifies the cause of the wake up. For instance:

The system has returned from a low power state.

Sleep Time: ‎2013‎-‎07‎-‎17T02:46:44.930338600Z
Wake Time: ‎2013‎-‎07‎-‎17T06:59:43.986364300Z

Wake Source: Unknown

The following is possibly relevant?

The start type of the Background Intelligent Transfer Service service was changed from auto start to demand start.

And there isn't much else. I had changed the Power Options from the default "Balanced" to "High performance" early on. Could that be related somehow? Also, I've already followed all the steps outlined here, which includes powercfg. I ran the following commands:

C:\Windows\system32>powercfg /lastwake
Wake History Count - 1
Wake History [0]
  Wake Source Count - 0

And

C:\Windows\system32>powercfg -devicequery wake_armed
NONE

And

C:\Windows\system32>powercfg -waketimers
There are no active wake timers in the system.

Also, I have my keyboard and mouse plugged in to my PC via USB 3 ports rather than USB 2. I'll try switching them to USB 3 and seeing if that works.

I've also got an ASUS motherboard with an UEFI BIOS, so I checked the UEFI BIOS for "wake-on-LAN" via the Boot Priority, and I only had it set to 1. Hard Drive, and 2. DVD drive. LAN was not listed there, like it appears in the screenshots in the instructions that ASUS provides.

Does anyone have any other ideas? I feel like I've tried almost everything.

This link describes what actually happens. By default the maintenance is set to 3 am and automatic wake up at this time is enabled.

It is easy to fix

Click on the flag in the notification area

Choose "Open Action Center"

Expand "Maintenance" and click on "Change maintenance settings"

Right there you will see the settings that is so arrogantly starts your PC in the middle of the night. You can either disable automatic wake up or change the time.

I did a few things, one of which solved the problem.

1. Changed from "High performance" power profile back to "Balanced".
2. In the "Balanced" profile's advanced settings, disabled "Wake timers" (even though powercfg told me that I had no active wake timers).

I suspect step #2 is what fixed it. The reason I didn't do this at first is because, as I said, powercfg listed no wake timers. By default, Windows has no wake timers enabled. But I guess this switch really forces it, so that must've fixed the problem.

I also changed "Automatic Maintenance" time from 3:00 am to 7:00 pm, so at worst, it would wake at 7 pm instead of 3 am. But this ended up not being a problem anyway, as I somehow fixed the problem.

Disable in settings: Power policy / Advanced settings / Sleep / Allow wake timers is Enabled for AC power

You may check in task scheduler processed to automatically run: Task Scheduler > Microsoft > Windows > TaskScheduler Double click tasks and you may disable: Activate computer to run this task

Check your BIOS configuration. There are options on a lot of motherboards letting you wake your PC up at specific times.