Use the /AnalyzeComponentStore to analyze the size of the Component Store (WinSxS folder) in Windows. The AnalyzeComponentStore option is available in Windows 8.1 Windows Server 2012 R2.

dism.exe /online /Cleanup-Image /AnalyzeComponentStore

Dism.exe removes superseded and unused system files from a system with the /StartComponentCleanup parameter.

dism.exe /online /Cleanup-Image /StartComponentCleanup

Using the /ResetBase switch with the /StartComponentCleanup parameter of dism.exe, all superseded versions of every component in the component store is removed.  All existing service packs and updates cannot be uninstalled after this command is completed. This will not block the uninstallation of future service packs or updates.

dism.exe /online /Cleanup-Image /StartComponentCleanup /ResetBase

The /SPSuperseded parameter removes any backup components needed for de-installation of a service pack. The service pack cannot be uninstalled after this command is completed.

dism.exe /online /Cleanup-Image /SPSuperseded