I just downloaded a new operating system in on my mac. I I pulled cs4 from the backup folder to the new startup drive. when i try to open cs4 it tells me error 6, contact support
There's the reason. You must install Photoshop CS4, not transfer it from backup or another machine.
Photoshop does not just install to the Application folder, it places support files all over your system. Moving also breaks activation.
Transfer: Just don't.
Copying, transferring or migrating applications is a monumentally bad idea guaranteed to bring you endless grief.