Try running the following at an Administrator Command Prompt..
DISM.exe /online /Cleanup-Image /StartComponentCleanup
DISM.exe /online /Cleanup-Image /SPSuperseded
DISM.exe /online /Cleanup-Image /StartComponentCleanup /ResetBase
Beware that after running this you may not be able to uninstall some updates. Your WinSXS folder should drastically reduce in size however.