Windows winlogon.exe causing unauthorised shutdown.

[xXNomyXx]

Hi,

I've been having an issue which happens completely randomly. Since the crashes there has been no hardware or major software changes other than the actual Windows Updates.
Here is the error which has been occurring:

http://puu.sh/aiHgb/8d0e8002c5.png

The shutdowns occur randomly and there is no partern in the time. The cursor will freeze in place, I'll still have complete control otherwise. After a few moments the PC will shut off instantly.

After some research online some pages point towards a PSU failure. Is it possible the PC is shutting down to protect itself and thePSU is actually failing? The PSU itself is nowhere near it's 550w maximum load.

If it's a simple as a PSU change then that's no problem. I'd just like to see if anyone else has had an issue with this in the past.

PC Specs: http://puu.sh/aiHwU/a5fdd0545f.png
Motherboard: asus sabertooth 990fx r2.0

PSU: CiT 550W Black Edition PSU 120mm Fan Dual 12v Model : 550UB

Thanks! Hopefully someone can shine some light on the issue.

[Maxibonbits]

If the error started after updating windows try rolling back the updates. The easiest way for this would be using system restore.

[xXNomyXx]

You say windows update caused the problem. But to my recolection they occurred before. It's only recently has it happened more often.