Windows 2000 and Windows XP won't install from a simple DOS prompt (following a floppy disk DOS boot).
Win2000 actually can install from DOS, since that's how I installed it on my 240. I have the IBM Ultrabay CD ROM drive, but it's not recognized by the Win2000 installer. With the appropriate drivers, it is recognized in DOS though. So I boot into DOS, and use the CD ROM drive to copy a .zip of the Win2000 install tree to the c: drive, unzip it, then install from the hard disk (use the i386\winnt.exe program to start the text-mode installer).

My current configuration is:
* 2 gig partition with DOS + Win2000, installed as described above.
* 4 gig partition with FreeBSD. This was installed over the network, so only the floppy drive and network card were needed.

I haven't installed Linux on it for some time, but it did work the last time I tried. I think RedHat 7.2 was the last version I used, so it's been a while. I assume that all the well-known Linux distros also support a network install.

I have an old Linksys 10baseT card and a newer Netgear MA401 802.11b card. These both work under Windows and FreeBSD. I will warn that even more so than Linux, the list of supported wifi cards in FreeBSD is quite limited. Many manufacturers have gone to chipsets that aren't open, so no drivers exist. I had to hunt around to find a refurbished Netgear card that would work.

It all works great. Win2000 isn't bad on this machine, and FreeBSD screams.