And what exactly? You need to be more specific. CS4 is a version moniker, not a program. We need to know what exactly you are missing and then we need to know computer specs as well.
My mistake It is photoshop elements 6 when I try to open it I get a message stating that it cant open due to missinig files, please reinstall I ran the disc and then it asks me to install disc I which I do not have !!!! Thank You