Hdd not recognized by mac?

Question

i have a 100 gig external hdd it worked fine for i would say 2-3yrs and now today i geta error that mac osx dose not reconize it disk utility only sees the disk and not the partitions i can not repair or mount ? im very confused o and btw its formatted by the mac ( osx 10.5.?) fat32 so it works on the pc and it dose it works on the pc and not on the mac now for some reason?

Answer 1

You didn't connect it to both the Mac and PC at the same time did you? Because that would cause corruption. Even if you never did do that, it could very easily be corruption. Try running disk utility on it or, better yet, Disk Warrior.