I use CCleaner Free v5.60.7307 (64-bit) on my WIN10 Home x64 desktop. Over the years I have been storing the cc_yyyymmdd_######.reg files on my HDD; about 45 now exist.
Is there any practical reason for me to retain these files? Should I retain all 45 files?
I just mistakenly ran a cc_.reg file that was created on Jan 13, 2019, thinking that its contents would open in NOTEPAD/text editor; I wanted to view the contents, only. To correct this, should I run the most recent cc_.reg file to overwrite the Jan 13th edition?
There's no need to keep all of them, maybe just the last one(s) Though I do advise caution in cleaning the registry so often. You really only need the backup files to solve problems that occur from the removal of registry entries mistakenly thought issues by ccleaner. See my signature below this post for good rules to follow when using the registry section
If you're going to clean the registry perhaps keep the backup .REG files for a period of 3 to 6 months. With registry cleaning any damage caused by it may not be obvious for months later.
Also your version of CCleaner it outdated, you can get a newer version at: