How Do I Remove The Write Protection From My Fat32 Formatted External Hard Drive

I tried it with my PC again, Windows 7 recognized it, but said it needed to be formatted before it could be used. When I tried to format it with Windows 7, it said the hard drive was write protected. How do I remove the write protection? Can I force the MacBook to mount the hard drive and remove the write protection? Any help would be greatly appreciated.

Thanks!