I have a PC at work and a MAC at home, and I would like to be able to use it on both computer. In reading the manual it shows that you can format the drive to either MAC or PC, but doesn’t show a set up to use it on both system. The My Passport Ultra is preformatted for Windows (NTFS), but it can be easily reformatted for Macs (HFS+). The drive comes with the WD SmartWare backup program, as well as WD Drive Utilities.

Samba is a linux protocol/program that creates a network drive on a 'server', this server could be your router for example, there are plenty of modern routers that support a USB-drive to act as a Samba drive. The advantage of Samba is that, once connected to it, the PC/Mac will recognise it as a standard drive, regardless of the filesystem of that drive (which is usually a Linux FS, for example NFS). The disadvantage is that it is indeed a network drive, so without the right infrastructure it is considerably slower than a local drive and of course susceptible to 'random network problem events', this is why I mentioned it requires at least some knowledge of networking. Considering you want local access, you could format part of your WD to be Mac friendly and the other part to be Windows friendly, I believe someone else in the thread already mentioned that option?

I'm not sure. When I bought the drive several years ago I only owned that Macbook Pro so it's quite possible I did. What would I need to do to make it recognizable by both? Then it probably formatted as HFS or HFS+ then. There are some free utilities that let you read HFS from windows but not write. OSX can read NTFS but not write.

If you plan on regularly moving data back and forth paragon's NTFS on Mac or HFS on windows are highly regarded and fairly cheap. You only need one. There are a couple of file systems both can read but they don't handle 1Tb very gracefully. Edit: exFAT would work pretty well for you actually.

But only if you have windows 7/8 and OSX snow leopard or newer.