I have used this device on a MAC and following a previous review that identified the need to re-format the disc for a MAC it has worked perfectly. I required the device as a background back-up (using Time Mchine) and I have now forgotton about it as it just does the job. In addition it is unobtrusive and fits in to my home office perfectly - highly recomendedGet more detail about Western Digital My Book Essential Edition 1TB USB 2.0 External Hard Drive.
