You actually have to exit the setup menu(f2 iirc), run a specific command, and then it will let you make an offline account.
If you don't have a NIC, it will make you get an internet connection before proceeding. That was my experience on my laptop. What had happened was that for whatever reason, my wifi card wouldn't work with the amd motherboard in my laptop (it wasn't cnvio, and it was the same issue with ac 7265 and an ax210). So I had to resort to that to install windows.
The one machine I had that ran Millennium Edition was a Sony laptop that came out right after it launched. Since it was the oem install, ig it survived for some time. My dad used it for Oracle DB work before I got it and used as a computer that could access the internet. I've only had one bsod with it. But realplayer deleted all my VXD files.