Hello,
I am running Windows 8(64bit). When I try to run the Disk Cleanup tool and select the "Windows Update Cleanup", the process is stuck while doing windows update cleanup.

let it run for a while. The TiWorker.exe compresses a lot of files in the WinSxS folder and this takes some time.

Here I've tried to explain what the cleanup does:

http://www.msfn.org/board/topic/153742-dism-improvements-in-windows-8/page__view__findpost__p__1043736

http://www.msfn.org/board/topic/153742-dism-improvements-in-windows-8/page__view__findpost__p__1015509