I had further thoughts about the wgatray issue. Perhaps the way you described it is misleading. You said you got a wgatray error and you deleted the various files. The icon can be quite annoying - I've deleted those files myself. Was it the other way round, you deleted the files and then got the error? The tray notification is only a visual indication to the User, it does not stop WGA from working. Whichever way round, it now sounds to me like that has nothing to do with your problems.
I'm still out of ideas.
I'm still out of ideas.