When there's a problem with the HDD (a Toshiba, I believe, but it's not in front of me now) and I connect it to the 202, it doesn't prompt to format. There is a page in the setup of the 202 that lets me, but it asks if I want to use NTFS or FAT. I formatted via my computer, instead -- first trying NTFS, but then the 202 couldn't recognize it, so I switched to FAT, and it seems to have started working again. I don't have a spare HD lying around to try it with. No errors recognized when plugged into my computer.