This post is a quick one on WinSXS cleanup, and it works (for me).
None of the instructions I found online helped me, including the KB2852386 fix on Windows update.
- Go to C:\Windows\system32
- Right click on cleanmgr.exe and Run As Administrator
- Now, the relevant “Windows Update Cleanup” option and another for cleaning up Service Pack backups should appear. Tick them both
For me this worked a treat for WinSXS cleanup.