Computer Turns Itself On Randomly

In your BIOS under Power Management you will find AC BACK. If it's set to Always on, set that to Always Off or Memory.

Also make sure the wake on LAN is off.

If you have a cable connect to the NIC, the router might send some signals if it's reset due to the power issue

A good place to start is going to the command prompt and typing powercfg /lastwake to see what was the last event that caused your computer to wake up.

There are a number of settings in the BIOS under Power Management such as "Wake on PME," "Wake on LAN," etc. Make sure they're all set to off.

Windows also loves to pre-schedule tasks like system updates, disk defrags, sending system reports to Microsoft, and so on, for the middle of the night, and sometimes it will wake the computer to do them. You can go to the Windows Task Scheduler (type "Task Scheduler" in the start menu search) and see a list of what it typically does. If you click on a particular task, you'll see several tabs below. Under the "Conditions" tab is an option called "Wake the computer to run this task." Make sure it's unchecked. For all of the tasks scheduled in the middle of the night. There could be like 60 of them, which was the way it was on one of my friends' computers. He had to go through and uncheck every one of them before it would finally stop waking up for no good reason.

all are off my computer goes completely off then it turns on not from sleep mode no wake on things are on but it maybe my usb devices interfering with the motherboard
it doesnt matter anymore i will just witch the psu off