For as long as I've used CCleaner, whenever I scan for issues, I get an issue that the problem is an unused file extension, and the data is " ? square ??? square ? square ? square Z ?? - " where square is an actual little square. Has anyone had this constant issue, or know how to fix it? It comes up in every scan I do.

Are you using any files from an Asian (or other foreign language) download or computer, as I've seen a few that have squares wherever the Computer (English based PC) can't understand the non-English letter.

Do you know of any files like this on your pc?
It could also be used by foreign cracks/hacks for pirating programs, as they often come from overseas.

English only for me, and nothing illegal as far as I know; I only use open-source and free programs, so I don't have any need for those. I also tried to open it in regedit, but all it did was open HKEY_CLASSES_ROOT, with no entry there, only the folders under it.

It's no big deal, I thought maybe if someone had experience with it, they had a fix for it, but I can deal!

Thanks for the reply.

Well I don't know then, unusual filetype anyway...
Are you having no other trouble with reoccurring registry entries.

You could try the fix for re-appearing registry entries here : http://forum.piriform.com/index.php?showtopic=8588

By the way good work sticking to freeware and staying away from pirated stuff.
I do the same, just I've seen some hacking software on other pc's using squares instead of letters.

I bookmarked that page and will try later today, looks just like my problem so hopefully it will fix it. Thank you!