There are quite a lot of cheap external HD units formatted only for Windows.
My son bought a Maxtor for his Windows machine today.  I persuaded him to
let me try it on the iMac OS X 10.3.9  It came up on the desktop OK and can
be opened, but will not allow transfer of files from the Mac.

Seeing as they are much cheaper than Mac compatible Maxtor models (if you
can find them) I am wondering if anyone has reformatted one for Mac and what
is involved?

Cheers, Paul