Windows Aero not working! D3DERR_NOTAVAILABLE errors! PC freezes HELP!

[NaryaMithrandir]

Hello Everyone!

create device failed
Error code: 0x8876086A
DX9AllocatorPresenter failed

D3DERR_NOTAVAILABLE


This was the error I received for many months when I attempted to play a game or watch a video through Media Player Classic.
At the same time, I always got the error that

Desktop Window Manager had stopped working and was closed

upon start-up, so I had no access to Windows Aero et al. Basically, the errors went hand in hand with each other.

Then after a while, the computer began freezing after 20 minutes of use. So now, even if I went and used Driver Sweeper to remove all old drivers for the GPU, and installed fresh drivers, the computer would freeze within 20 minutes of use. (Previously to that, a fresh install guaranteed no problems atleast for a week)

I finally decided it had to be a GPU error, so I sent in the GPU for repair at ASUS. I still haven't received it back, but in the meanwhile, installed an old BFG 7800GTX I had lying around to have a temporary computer.

AND LO AND BEHOLD, I HAVE THE SAME ISSUES.

What do I do now? Clearly it means it's not the GPU's fault. Is it the RAM? The Motherboard? Maybe not enough power to the system? I'm at a complete loss, and really need help!

Here's the System Build:

CPU: Intel Core i7 2600k
MOBO: ASROCK z68 PRO 3-M (MicroATX)
RAM: Crucial 8GB GDDR3 1600Mhz
SSD: Crucial m4 128GB SSD
SATA Drive: WD Caviar 500GB SATA 3.0 Gb/s
PSU: Antec True Power Trio 550W PSU
GPU: ASUS ENGTX460 TOP Direct CU 114% OverClocked 1GB [Currently a BFG 7800GTX since the other one is at the repair centre]


Please help! I appreciate any advice.

Thanks.

 

[NaryaMithrandir]

I should no also add that when I go to My Computer, and click on System Properties, computer hangs, saying

Windows Explorer has stopped working

And then it goes ahead and re-starts Windows Explorer. In this way, I am unable to even open System Properties now.

OH DEAR...