iTunes and Quicktime issue (Please Help)

So last night I download the update for iTunes. Everything seemed to be going fine, I didn't have any problems. This morning I turn on my computer and try to run iTunes and it gives me an error message, an dwon't even open iTunes. Not only that, I can't run any Quicktime file, it gives me the same message. I downloaded the installer again and attempted to repair iTunes. It said I was sucessful, but when I tried opening iTunes or Quicktime the error still appeared. This is really frustrating, this is what I get for updating? Someone please help!