Why not try copying all the files and data into your MBP or another HDD, run DISK UTILITY in UTILITIES and ERASE the HDD, formatting it with MS-DOS FAT format at the same time? Both Mac and PC can read and write it after formatting. Same goes for any flash drives. After that, copy the files and data back into your newly formatted HDD. It takes less than a minute to ERASE and format the HDD to MS-DOS FAT.
FAT is inherently less stable and there's the limit of max 4GB partition. http://support.microsoft.com/kb/100108