No. They will happily co-exist on your hard drive.
Thanks John. I have bought a new iMac and wondered if I needed my old software on it before upgrading. Any idea?
CC is not an upgrade ,you can install CS5,CS6,CC and CC 2014 and you'll find them all separatly on your application folder but installing CS5 on your new machine (normally MAC OS 10.9 or 10.10 ) won't work correctly ..
wondered if I needed my old software on it before upgrading.
"Upgrades" are all full versions of the software. They don't depend on prior versions being installed in order to function. Upgrade licensing just means you pay less because you already own a previous qualifying version.
In the case of Creative Suites (CS5, CS6) "upgrade" only refers to the serial number.
In the Creative Cloud there are no serial numbers. They're activated via your Adobe ID. The versions available in the Cloud (CS6, CC and CC 2014) are all full versions containing full executable code.
You know your stuff! Many thanks. Was just backing up everything onto time machine, photos, iTunes etc so I will leave out all the adobe software and get CC downloaded.
Thanks John for your help