I/O Device Error Help please

Hello again,

This time, another External HD of mine is getting an error..

I have a Windows XP laptop, and a 500GB WD External HD (FAT32)

—connected by 2.0 USB or firewire (both gets error message)

I tried to open my files and i get the following error..

“H:// not accessible

The request could not be performed because of an I/O device error”

Some help with this?