I have done it, I built my nf7-s system with win2kpro, at the same time i built the same system for a good friend. He happens to be stuck with win98se because he has an old 1-way cable modem that will not operate under 2k/XP. I had a bit of a tough time getting windows installed on the raid-0 array, a couple updates from microsoft's downloads site, and some work with fdisk, and i was in there. Not that big a deal at all. One thing to note, is that soundstorm currently has a problem under win98. If you experience problems with mp3 playback and other things, you will need to set the hardware sound acceleration down to "basic". that will fix that problem at least until we have some newer sound drivers. You can PM me if you have any problems getting it set up, but it should work out fine for you.
J.