[derm318]

Is there a way that one HD can backup both Mac and Windows files? If so, which external HD would be best for this task?

[mduell]

Yes, format it as FAT32, then you can read and write from OS X and Windows natively. Or format it as NTFS, which is native for Windows and requires a piece of freeware for OS X. Or format it as HFS+, which is native for OS X and requires a piece of payware for Windows.

Any external HD is fine.

[derm318]

What freeware is needed if I format the drive as NTFS?

Norman

[mduell]

macfuse - Google Code and NTFS-3G Read/Write Driver Home

[dmullins]

Don't you need an intel mac to run both windows and OS X?

[mduell]

Originally Posted by dmullins 

Don't you need an intel mac to run both windows and OS X?

On the same machine? Yes.

The OP never mentioned he was running Windows and OS X on the same machine.