Ok, there are a whole lot of issues with this upgrade. This upgrade path isn’t supported by Microsoft. Not only may there be hardware related issues, but in addition, you would have to upgrade to Windows 2000 Server first, then 2003. This is the smoothest path.
Ironically, I am finishing a final draft of an upgrade of an NT4 network to 2000 that may be of some help. I will be posting this on my Website at http://www.iis-resources.com in the coming week. If you wouldn’t mind shooting me a direct email, I will forward to you, in its rough format, so that you may get started in the next few days.