Run a clean install. You'll be much happier in the long run
I think you won't be happy with the results if you just upgrade. I've done a few winNT->win2k upgrades and winme->win2k upgrades and almost all of them were unstable in some regard.
also winnt32 is the presetup program that win2k uses, to take your intial install choices and copies all the setup files to the hard drive...if that helps.