The temp files are (IIRC) a combination of the temp folder in your user profile and c windows\temp. You'll need to actually look in the folders to see what all is in there, but I expect the actual ...
Once a week I do a whole-volume backup of C: with Macrium Reflect. Usually I start by running Disk Cleanup, so the umpty-ump megabytes of crap don't have to get copied to my backup. Ever since ...