During install of CS 5.5 Des Prem, it asks for previous version and I entered a legitimate, upgrade version 4 product key code but does not accept it. In the past we've had to call Adobe support and we would give them a challenge code and in return, we'd receive the support/response code. They told me to post this question forum because of the version I have, a retail one as oppose to volume license. How do I retrieve a support/response code???? Any assistance is appreciated.
Adobe Support is the only resource for getting serial numbers.as far as I know.
Chat support - For the link below click the Still Need Help? option in the blue area at the bottom and choose the chat option...
Serial number and activation chat support (non-CC)
http://helpx.adobe.com/x-productkb/global/service1.html ( http://adobe.ly/1aYjbSC )