This folder is the repository of all the components store of the operating system, where each component has a unique name that includes the version, language, and processor architecture that it was built for. This folder is the only location where the component is found on the system, all other instances of the files that you see on the system are “projected” by hard linking from the component store.
This feature is also responsible for why you will no longer be prompted for media when running operations such as System File Checker (SFC), or when installing additional features and roles.
There are a few directories in the component store so let’s look at their general role is in Windows.
WinsxsCatalogs: Contains security catalogs for each manifest on the system
WinsxsInstallTemp: Temporary location for install events
WinsxsManifests: Component manifest for a specific component, used during operations to make sure files end up where they should
WinsxsTemp: Temp directory used for various operations, you’ll find pending renames here
WinsxsBackup: Backups of the manifest files in case the copy in WinsxsManifests becomes corrupted
WinsxsFilemaps: File system mapping to a file location
Winsxs<big_long_file_name>: The payload of the specific component, typically you will see the binaries here.
When we update a particular binary we release a new version of the whole component, and that new version is stored alongside the original one in the component store. The higher version of the component is projected onto the system, but the older version in the store isn’t touched. The reason for that is the third part of why the component store gets so large.
Also, as you patch your systems and add new roles and features, the winsxs directory will also grow in size.
There are few commands available that can be used to create the space however we need to understand the later effects of running those commands. For example –
DISM.exe /online /Cleanup-Image /Superseded
DISM.exe /online /Cleanup-Image /StartComponentCleanup /ResetBase
(Deployment Image Servicing and Management (DISM) is a command-line tool that allows you to install, uninstall, configure, and update Windows features, packages, drivers, and international settings.)
We should not touch the winsxs folder and be as it is until you are an expert or have full knowledge about it, as it can impact your system adversely.