Are you talking about Windows 2000 or NT here? As you've posted in a
Windows 2000 group, I assume the former.
With NT, there was no Microsoft-approved way to achieve this. With Windows
2000, are standalone or domain members until they are promoted to be a DC
using dcpromote.exe.
By promoting to DC, you will lose any local accounts defined on the box.
Incidentally, the concept of PDC/BDC is non-existant in Windows 2000 Active
Directory. There is only a nominated machine in each domain that has the
role of PDC emulator so that any NT4 BDCs in the domain know which 2000 DC
to talk to.
Regards
Oli