1.) How "full" is "getting full"? Go to Windows Explorer. Hold your cursor over the C:/ Drive. RIGHT click. In the drop down menu==>PROPERTIES will tell you how full or empty your computer has become. If you are running Windows 10, there is a DISK CLEANUP button there. Use it.
2.) Go to START (bottom left corner at Microsoft logo) SETTINGS==>APPS, sort by SIZE and see if there are any large applications that you do not want, then UNINSTALL them. This is probably not going to retrieve a lot of space, but it will get rid of unwanted applications and their bulk.
3.) You do not have to seek the TEMP files to delete. Start off with CTRL-SHIFT-DELETE simultaneously. This is the acceptable "first volley" against TEMP file storage.
At the drop down menu check ALL of the boxes and let your machine's software, the software put there by Microsoft for this very thing, do its best to delete the junk in TEMP folders. Repeat the process multiple times to be sure. On exit, CHECK the box that removes this junk every time you turn your computer off.
4.) Go to RECYCLE BIN and EMPTY it.
5.) Turn OFF your computer for 20-30 seconds and turn it ON again. Check disk space as in 1.) above.
6.) Download and run Freeware (link) CCleaner
. RUN cleaner and only clean/remove the files from the default setting, to sweep the dust out of the corners.
7.) Download and run Freeware (link) defraggler
click the ▼ by defrag and select "quick defrag". It will offer to empty your recycle bin say yes. This doesn't remove anything (besides emptying the recycle bin) but it organizes your files so your computer runs better.