I have an external NTFS HDD containing my music library that is
connected via USB to an XP Pro SP3 machine. Bought a new machine with
64 bit Win 7 Home Premium.

Can I unplug that HDD from the XP machine USB port, plug it into the
Win 7 machine's USB port and have it be recognized and accessible by
Win 7?

If I then disconnect that HDD from the Win 7 machine, plug it back in
to the XP machine, would it still be accessible by the XP machine?

i.e., can I physically swap a USB connected HDD between XP and Win 7
machines and have it work on both?