Windows 7 - DWM.exe won't initialize, error code 0xc000007b

Hi, I just got my laptop back from best buy, they had to replace a fan and apparently re load windows 7. All was fine and I began running windows updates. Eventually, the computer, while booting got hung up on one update (fatal error code c000003a). I restored the system to the earliest date and finally got to log on. Everything seems to work great now, except I noticed the windows aero theme was disables. I Hit the find out what's wrong with aero button and it didn't return any results. I also checked "services" and saw that"desktop manager session windows manager" was started and set to automatic, but when I click that and hit restart service, I get the same error. Before I got this error, I got a different one that said I was missing "dxgi.dll", I downloaded that and put it on my system32, just though I'd let you know. I'm running windows 7, home premium 64-bit. I'd REALLY appreciate any help!

thanks