Suggestion -- install Windows first. I recall reading several years ago, that during installation Windows would wipe out any other system it found on the drive. Caveat: I have no personal knowledge whether this is true or not. (The last time I set up a dual-boot system was in '98.)
I've used Mandrake and RedHat for years and generally liked them, but I recently dumped RH9.0 for Knoppix after I saw a big increase in performance in the latter using their LiveCD (which I subsequently installed). Thinking now of moving over to straight Debian.
Appreciate the info- that's what I vaguely recall too, but since Win2K is already resident, it shouldn't be a problem. MandrakeLinux claims it will dynamically repartition the drive and install a dual boot loader. I cloned both drives, just in case... better safe than sorry.