How do I reformat my time machine backup disc
My time machine backup disc comes up with error:
Files can’t be copied onto the backup disk because it appears to be read-only.
Disc utility can't fix it and gives me the following message:
Disk Utility can’t repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files.
How do I reformat that drive?
iMac, Mac OS X (10.7.3)