Unused File Extensions

I used CCleaner to scan for issues and it found some unused flie extensions (UFE). If I delete them will I then not be able to use them?

ex. One of my UFEs is .z64. It is a N64 emulator file. If I delete the entry will I not be able to play .z64 files?

Any help would be greatly appreciated/.

welcome to CC.

its most likely that the emulator will just recreate that extension when you run the program so i doubt it would matter if you fixed that issue.

(just be sure to backup your registry when it asks!)

-aaron