I had a similar problem before, i think it has something to do with media player 11 beta, this should stop the errors but its not a fix.
1) Open a command window (Start->Run, type in 'cmd' hit enter)
2) To remove media preview, type and hit enter
regsvr32 /u shmedia.dll
If you need to restore media preview, type and hit enter
regsvr32 shmedia.dll