So my daughters 24" iMac (don't know what she's running on it) has a software problem, so said the kid at the Genius bar. Boot up goes no further than the spinning icon. I wasn't sure how much she has backed up, probably very little if I know my daughter, so I told them to hold off installing the new software (free they said) until I bought an external HardDrive. They weren't sure how much if any of her stuff would back up ("anywhere from nothing at all to maybe everything") if they were able to get me into the present system. Is this the only option I have available with her computer? That is, hooking up the external HD and trying to back up at the Apple store? Thanks in advance.