I often get people telling me that their Windows 10 size is now massive & out of control, & asking what can they do about it? The culprit is the WinSXS folder, or Windows Side by Side – it’s full of previous versions of files replaced by Windows Updates & used in case of a rollback being needed. Nothing gets auto-deleted, it’s a retirement home for old files & really, a clumsy klutz of a hot mess. Surely MS could have managed this thing better, especially as seeing it’s the biggest folder in your Windows install & not actually used. Long story short, to clean it up somewhat press Winkey + E, right-click on C: drive. Properties / Disk Cleanup / Clean Up System Files – make your selections & hit OK. It’ll take a while longer than usual to delete this rubbish but your gains will be multiple GB.