Computer turns itself back on

[Thalin]

My PC has decided to turn itself back on straight after I shut it down, as if shut down counts as restart. I've looked in the BIOS, power options etc, and see no reason for it doing this. Wake on Lan is disabled, 'reboot on error' option is disabled.
I get the same problem when holding down the power button to turn it off too.
This has been happening to months, and i'm sick of it now. The amount of power that it must have drained from being left on is ridiculous.

Any ideas?

 

[Rik]

Courtesy of Howard, take a look at this - http://aumha.org/win5/a/shtdwnxp.php

 

[Thalin]

I've looked through that already. Nothing there seems to work.

 

[Rik]

Then perhaps your psu is faulty and in need of replacement.

 

[Thalin]

It's a fairly new PSU though, Antec TruePower 550W bought only 6 or so months ago.

 

[Tedster]

read: https://www.techspot.com/vb/topic55506.html

 

[swiiliams1988]

I had the same problem a while ago, seemed that all which was wrong was one of my ram sticks wasn't inserted properly.