Aero themes not working unless I restart the PC

I also tend to get some random BSOD if I don't restart the computer (while aero isn't working). I checked services, windows desktop sessions manager is running. When I restart the service, it flashes for a second and changes to aero theme but then back to windows 7 basic layout. I've run sfc /scannow and got no errors. I've also done a clean install of windows sevral times with no luck. Any help would be greatly appreciated. Thanks in advance!

Windows 7 Ultimate 64-bit
AMD FX-4100 3.6ghz Black Edition
GeForce Asus GTX 550 Ti
ASRock 970 Pro3 R2.0
2x4gb Geil Enhance Corsa 1333MHz Dual Channel
Deer DR-8600BTX 600W
Seagate Barracuda 500gb

Tookeri said:

Try this: Guided Help: Troubleshoot Aero problems in Windows 7

It also says this:
Note To use Aero, you must meet the following requirements:

• You have to rate your computer first (Windows Experience Index).
• Your computer must have DirectX 9.0 or a later version installed. Or, your computer must have WDDM 1.0 or a later version installed.
• Aero is not available in Windows 7 Home Basic.

I tried the link you posted but "Troubleshooting couldn't identify the problem". Also I don't think my computed doesn't meet the requirements since it can display aero themes just fine, but only after I restart it once.

Tookeri said:

That's true and very strange. What I was thinking with these notes on that page was if you have remembered to rate the computer using the Windows Experience Index after every clean OS install. Well at least the last one in this case.

Another thought: are you using Sleep or Hibernate? If so that might be the reason it requires a "clean" reboot to work.

I checked Windows Experience Index and my computer was already rated 5.9 (so I guess I had already done it in the past) but when I press "re-run the assessment I get the following error: "The Windows Experience Index for your system could not be computed. Cannot complete assessment. The assessment or other operation did not complete successfully. This is due to an error being reported from the operating system, driver, or other component." What could be the problem?

Edit: I'm not using neither sleep nor hibernate.