In an attempt to mount an external hard drive onto my iMac, I attempted to put in the original install disk (10.4.7) and re-installed my OS. I was upgraded to Leopard but now I accidentally re-installed Tiger. When re-installing it told me that Leopard would be saved under "Previous System" or something like that. I've looked for this folder or a way to restore my system but nothing has worked. I was not using Time Machine. All of my applications (such as Final Cut) are still there, but "cannot be opened on this OS". Any help or advise for restoring my computer to Leopard would be appreciated Thanks!