When I try to install, I instantly get a message that Setup has encountered an error" and nothing else, then setup terminates itself.
What can I do? I am running OS Lion
To be correct you are installing the CS3 , which suite or Product?
You are installing from teh DVD or the back up copy?
If back up copy then where is it saved?
have you tried installing from new user account?
We need much more info and possibly install logs. That aside simply be aware that this could be compatibility issues and it may never at all install.