If you install XP first (before Vista) and the XP hard drive is
connected so that it is visible to the Vista installer, the Vista
installer will make the dual-boot menu for you. This does
affect the XP restore point function, though. Read up:
http://bertk.mvps.org/html/dualboot.html.
If you install Vista first (before XP), you will have to use a
3rd-party utility to set up the dual-boot for you. One such
utility is VistaBoot Pro:
http://www.vistabootpro.org/
You could also use the BIOS's Hard Drive Boot Order
to set the priority of the hard drives so that the HD with
the desired OS gets highest boot priority. Just install each
OS with its HD as the only one connected during the
installation process, and the HD getting control at boot time
will boot its resident OS as a mono-boot. The *default*
HD Boot Order is:
Master, IDE ch. 0,
Slave, IDE ch. 0,
Master, IDE ch. 1,
Slave, IDE ch. 1.
This will determine which HD boots in the default case.
But by changing the HD Boot Order in the BIOS, *any*
HD in the system can be made to get control at boot time
and to load its resident OS.
And, of course, if the removable HDs are the only ones
in the system, if you remove one, the other HD will
automatically get control at boot time.
If you haven't yet chosen your removable HD "mobile racks",
check these out for IDE hard drives:
http://kingwin.com/product_pages/kf101ipf.asp
They come in beige (above) and black:
http://kingwin.com/product_pages/kf101ipfb.asp
with a fan in the bottom of the removable tray.
The set generally sells for $22 on the Web, plus shipping.
Extra trays sell for around $5 to $7 less.
I have such a mobile rack with a bottom fan, and the
bottom fan really keeps the hard drive cool. Kingwin
also makes racks with front and rear fans and racks
for SATA hard drives.
Files can be transferred by simple drag-n-drop between the
2 hard drives.
*TimDaniels*