External HD + 2 computers = unreadable files?

[Build One]

So, my father-in-law purchased himself an external HD on my recommendation that he will be able to move files from his WinME desktop and his WinXp laptop with grace and ease by simply moving the ExtHD from one computer to the other.

Now, he calls me today to tell me that the files he has on the brand new one day old external drive can only be seen by the computer that put them there. Meaning: Computer A can only see files on the drive that computer A put there. When he moves the Maxtor external HD to the laptop (computer B) NONE of the files form computer A can be seen...yet, all the files that the laptop put on there CAN be seen. Am I confusing anyone yet?

I have researched for the last 3 hours trying to find a solution for him. Once more, the ExtHD CAN BE SEEN fine by both systems just the files created by 'other' computers can't be seen.

Any ideas?

[EzyStvy]

Is the ext drive formated Fat32 or NTFS?

[Build One]

Well, according to the Maxtor website all their drives come as FAT32.

[TwoRails]

Ya, their external drives are FAT32, and should work in any system, even if one is NTFS. Does he using any file encyription or compress or passwords or the like?

[glc]

I would repartition and reformat it in the ME computer to FAT32, put no files on it, hook it up to the XP computer and get it recognized - then try working with files again.

[Build One]

Alright, I'll have him try the reformating.