I bought my first portable hard drive two weeks ago and had no problems installing and using it. I then bought a second portable hard drive so that I could store one off-site while I used the other. The second portable hard drive will not backup my files. the following message appeared on my screen: "Time Machine could not complete the backup. The backup disk is not in Mac OS Extended (journaled) format, which is required." As nearly as I can tell, the disk is formatted in Mac OS Extended (journaled) format, BUT it is in read only status, and I cannot figure out how to change that. Anyone have an idea of how I can get my second portable HD to work?