CC Cleaner compatibility

I really want to update the above but I am concerned it may interfere with my internet protection software.(Norton 360 Antivirus etc). I was told once that 2 similar packages may slow down the computer speed. Have I got it wrong?

Ccleaner is not an antivirus so there should be no slowdown. The slowdown you refer to is likely about two antivirus or two firewalls

At this point I think the documentation of CCleaner needs to state: Not an antivirus or anti-malware

I've seen where too many people are thinking it is an antivirus or anti-malware when clearly it is not.