I want to install Mac OS X Leopard on my external hard drive so I can use it as my back up drive. When I do this, do I have to back up all the files on the hard drive or they wont be deleted?
or use time machine and time capsule and you don't need to install mac os x on it cuz it just runs and brings up your computer exactley how it looked however long ago you select
Why do you want to install an OS onto the external harddrive? Surely if it's formatted to Mac OS Journaled you can just drag and drop the files you want to backup or alternatively use time machine to create automatic backups? But bare in mind windows computers will have trouble reading/writing to this format though.