Just format it with the built-in Windows formatting utility, assuming you're using Windows.
Were it that I could. For some reason, my Windows XP computer thinks this thing is a C D!!! Seems as though WD installs some sort of firmware that makes it emulate a USB connected CD.
This is a 750GB WD My Passport Essential. It now says it is a CD of 641MB AND I have NO DATA readable.
I can't figure out how to get around this firmware to make it look like my other USB drives (I also use for external backup and storage).