Just a head up from a problem I ran into. When installing a USB Passport drive for the Mac, Finder didn't list it and Disk Utility did see it and was able to format it but then showed 100% full. Apple support helped turn my attention to ESET, and I found one of the upgrades by default enabled "removable media blocking," which prevented me from using the Passport drive or any other. Turning that setting off solved the problem.