I'm planning to use a HDD (IDE, NTFS) removed from an IBM Thinkpad as an external backup device through USB. The instructions that came with my hard drive enclosure state I must reformat to FAT16 or FAT32 before placing in the enclosure. Is there a technical reason why it cannot be NTFS? Is it just for compatibility reasons? Google has not provided a clear answer so far. I found one forum which suggested NTFS extrnal drives and XP (this will be connected to XP and W7 machines at least) "do not play well together", but was inconclusive. Anyone come across this?