I performed a disk repair so I could partition my HD for a windows OS, Now I keep getting this message."Back up the disk and use Disk Utility to format it as a single Mac OS Extended (Journaled) volume. Restore your information to the disk and try using Boot Camp Assistant again". Not sure what to do at this point, Ive also never backed anything up on a Mac before, so Im pretty lost there as well. Also, is there any way I can do this without backing up my disc with an external HD?