Hi everyone, I have to back up my macbook on an external hard disk in the coming two days to send in my laptop for repair. My 3 year applecare expires in 3 days so this is very urgent. I was told to reformat the external harddisk to the apple/mac journal format before saving my backup on it. My question is: Can do this with an external hard drive that already ahs data on it- and a different formatting? I want to borrow my friend's external hard drive but she has lots of files on it. I assume that reformatting the drive would result in her losing all her files. Is there any way to backup your mac to an external harddrive that ahs other stuff on it and not solely dedicated to the great purpose of backing up your macbook? Thanks a lot!