OK the only processes I see, that could affect WMP and the CD Burning abilities would be the MediaFoundation Plug (mfpmp.exe = DRM) and AVG.
But I think you had both installed already when everything still worked a week ago. So let's take a different approach and restore the system back to that point in time when everything worked fine (~8-10 days ago)
System Restore
CDEX you can always install later as a last resort so to speak

-DG