7z file manager crashed and left temp files behind

Using the run command: (WIN+R) type "%TEMP%" and hit enter.

This will bring up all the temp files stored on your PC through the user account you are on.

7-zip tells you the temp location it uses (extract from 7-zip.org/faq.html):

7-Zip doesn't know folder path of drop target. Only Windows Explorer knows exact drop target. And Windows Explorer needs files (drag source) as decompressed files on disk. So 7-Zip extracts files from archive to temp folder and then 7-Zip notifies Windows Explorer about paths of these temp files. Then Windows Explorer copies these files to drop target folder.

To avoid temp file usage, you can use Extract command of 7-Zip or drag-and-drop from 7-Zip to 7-Zip.

C:\Users\xxxxx\AppData\Local\Temp under windows 8.1

found MANY 7zipExxxx.tmp folders ...using up 16GB ! reboot did NOT help. Using CCleaner did NOT help. Manually looking at TEMP folders did NOT help.

What I did was use WinDirStat to see all my files and lo and behold 7zip was not clearing a thing.

Hope that helps others.