When running the Analysis function my CCleaner would stop progressing I started running the Clean function the system would also stop progressing.
I then went thru the Windows and Applications options and boiled it down to FireFox (FF) Internet Caches and FF Compact Databases. Not only do they stop progressing they also cause the program to drop into Not Responding when Cancel is selected.
Somewhere during this it asked if CC should shut down FF. I OKed that, as I did not know FF was running.
All this working on my wife's FUJITSU LH531 Notebook with Windows 10 64-bit 4GB RAM Intel Pentium CPU B950