It could be, that when you installed WinXP, you had the other drive
present as well. I disconnect the other drives before doing
an install. If I needed to manage all the OSes from one place, I
might use Boot Magic from my Partition Magic CD. It allows a
user to add entries to the menu, after an OS is installed on
another disk. There are many other boot managers, but they tend
to be "greedy", and update their menu for you, and somethings
that can go horribly wrong. I like to fix up the boot issue
myself, after the dust has settled. My current machine isn't
managed by Boot Magic, and I use the F11 key to select a
boot drive from the BIOS. So my BIOS is my boot manager right
now.
In terms of BIOS issues, on my current computer, the BIOS
drives me crazy. The BIOS has its own scheme of numbering
drives, and if you install Linux, the Linux installer uses
the BIOS numbering scheme. This caused me to have the MBR
on my WinXP disk erased, when installing Linux on a completely
different disk. As a result, I recommend disconnecting
everything that might get trashed by a well written installer :-(
I don't really understand what is going on, and why the
BIOS labeling of drives, has to change as a function of
which drive is the nominal boot drive.
When you add a drive, it is going to need a drive letter for
every partition that you prep and format. The letters can be
assigned manually, using Disk Management. So you can lift them
up high if you want. For example, I have a disk at S:, whose
label is Scratch. I have a certain number of partitions that
fall where they may, down low. And as a matter of practice, right
after I install an OS, I always move the CDROM out of the way as
well. Perhaps move the CD to Q:. Since I do that immediately,
if I then install Microsoft Office right afterwards, the registry
will be filled with references to Q: instead of some other low
drive letter like D:. Your CD should be in a stable place, so that
there won't be an issue with references to that optical drive later.
By picking Q:, my assumption is that the drive won't get bumped
due to other randomly placed volumes.
In terms of compatibility, if you have some OS which does not
understand 48 bit LBA (>137GB), then that OS could corrupt
the disk if it manages to recognize a partition (NTFS or FAT32
say) and attempts a write to them. So that is an exposure you should
consider. I have to be careful here, as I have one out-of-date
OS frozen at a certain Service Pack, and if that OS writes
to my 250GB SATA drive, there could be trouble. Right now,
all the partitions on that drive are below 137GB. And that
makes it safe to boot that OS, with the SATA drive connected.
I've read that USB devices can have drive letter problems.
For example, network shares and USB drive letters don't know
about one another. A network share can grab the drive letter
from a USB device. Uwe Sieber's site has more details. He also
has some good info on some issues with USB and Windows.
http://www.uwe-sieber.de/usbdlm_e.html
http://www.uwe-sieber.de/usbstick_e.html
Paul