You'll have to copy out the files you want to save then format the drive in an Apple supported file system.
Maxtor External HD 250 GB
I recently switched over to macs from an hp pc computer. i have a maxtor external hd that went along with the pc and i saved all of my music/videos/movies on the hd so that i could bring them into my new laptop. i've installed the cd that came with the hd and while i can delete/copy/bring files into my computer, i cannot add or bring anything into the hd from my mac. i've scoured over google/this forum/the world for an answer and i have yet to come across one. PLEASE HELP!!!