I had to reinstall my Mac OS, but now Photoshop says "One or more files in the Adobe Application Support folder necessary for running Photoshop are are missing. Please run the Photoshop installer and re-install Photoshop". So using my original install CDs for CS everything is fine until the window where I'm told to check which software. But all the options are grayed out so I can't check any. So I can't proceed, the only button operable is Quit. Why are they all grayed out? What's going on?