What windows update are you referring to? If you converted from Windows 7 and you have no intention of going back, you can delete that file(windows.old) - but ALWAYS use the disck cleaner in Windows for this.
The Rolling Cache file is allocated in Windows to the amount of space you have it set to in the sim - whether it’s full or empty. So, if you allocated 16gb… it will reserve 16gb at all times.
There is a way to move your Rolling cache file to another drive if you want to.
If you don’t know whats taking up that new space, get yourself a software utility like TreeSize to see whats eating up your space. Also, CCleaner is now safe to use. It’s been cleaned up, so to speak - no more spamming.