If its file system agnostic then why does the USB drive have to be FAT formatted?
It doesn't *have* to be FAT-formatted. However, USB drives are typically FAT-formatted because of the quick-eject nature of the drive. You can only format them to NTFS if you tell the system to require you to use the "Eject" feature of the "Safely Remove Hardware" icon (since NTFS is journaling, removing while there are still cached actions to be done can leave the file system in an inconsistent state).
I was merely mentioning FAT for illustrative purposes. I demonstrated that this was the behavior using NFS (Network File System) as well.
The two parts of my reply went hand in hand, you can't answer half of it and ignore the rest!
Especially when your answer to that question contradicts the statement in the latter part of my post!
As this screenshot shows, autorun.inf is clearly modifying the label for my usb drive just fine, but it is definately not autorun-ing the specified executable or changing the default action of the drive. I don't doubt you are right, but obviously its not working here