BU domain cotroller on .net server…

I currently have a W2k server which serves as my DC. I have a spare server (currently a Terminal Server), loaded with .net. I’d like to make this second server a secondary DC. When I ran DC promo it said I needed to run ADprep due to imcompatibilty issues. Any thoughts? Has anyone encountered this? I’m not familar with ADprep.

Basically, I can’t get the .net server to become a DC for my local domain….

Thanks