Well, in any
case, Windows-ME is the last version of Windows that was based on MS-DOS. It has no
built-in security, no decent implementation of the Windows32 environment. It is a very unreliable platform compared to the ones that have succeeded it.
As much as I might despise giving praise to Microsoft ...
... the Windows-NT platform (which underlies WinXP and the like) really is
much better. You should therefore be able to eliminate Win-ME from the picture completely. You should be able to adapt any applications which seem to be reliant upon WinME so that they run satisfactorily under WinXP, and you definitely want to do that. This would reduce your triple-boot situation to double-boot, and then, as I strongly recommend, you can convert that
to "two separate computers."
Let's face it... computer-stores around the world are chock full of "cast off" computers that, if viewed honestly, are anything but
"cast-offs." Even if you stack two computers on top of each other and buy a keyboard/video/mouse (KVM) switch, it's a much more practical arrangement than dual-booting, imho.