Digging up this from the past, Tony. What did you end up doing? I have a server as standalone and want it to become a BDC to sync things up and then a PDC to take over from the old PDC. I've read that generally this isn't possible. One utility called upromote will do it apparently, but I need to do it fairly quickly (and cheaply).

I found another post of yours here in this thread. Is that what you did? I can't get it to work at the moment.