Just today I got a notice my SSD was getting too big. Taking a look further, it seems the culprit is winsxs file. I've had this computer for 4 years and have never seen this. It is 35gb in size, that folder alone. What is going on?
Take a look here: https://support.microsoft.com/en-gb/kb/2852386
When you install updates, Windows keeps a copy of the original files along with the newer files. Those copies are located in the WinSxS folder.
Note: If you run the Windows Updates cleanup you may not be able to roll back installed updates (if you need to) without reinstalling them first.
Also just know that Windows Update cleanup is somewhat broken right now, it is currently removing updates it is not supposed to. So you may have to reinstall a few things after running it.
See here:
FYI: Extended Disc Cleanup has started killing recent Windows Updates
and here
KB3023607 repeatedly removed by deepclean after - Microsoft Community
Quote