You can't delete the WinSxS folder, but you can clean up its contents to free up space on Windows 10, and in this guide, we'll show you how.
On Windows 10, "WinSxS" (Windows Side by Side) is an essential folder within the "Windows" folder, which contains most of the components to customize and update the current installation. For instance, inside the WinSxS folder are located the files to add or remove features, switch editions, recover damaged or missing system files, and pretty much everything else that makes up the OS.
Full story from the WindowsCentral blog...