https://cyberraiden.wordpress.com/2014/05/06/360-total-security-review-settings/When Windows installs updates, it drops the new Windows component in the WinSXS folder and keeps the old component in the WinSXS folder. This means that every Windows Update you install increases the size of your WinSXS folder. This allows you to uninstall operating system updates from the Control Panel, which can be useful in the case of a buggy update — but it’s a feature that’s rarely used.
https://technet.microsoft.com/en-us/library/dn251565.aspxOne commonly asked question is can I delete the WinSxS folder to regain some disk space? The short answer is no. However, there are ways to reduce the size of the WinSxS folder.