Cannot logon new user

I have created a new user account of the PDC, but when I try to log that user in, I get an error message that “logon name or password is not correct…” I have created the user on the local machine, which was a PDC that went off line and I had to demote to a BDC and never promoted back to PDC. Is that my problem? I’ve tried just about all I could think of, setting no p/w, creating simple p/w.
Another possiblity is that on the new PDC, under server manager it lists this machine as a workstation, not as a backup. My next step is to re-install NT and only install as WS. Thanks for any help!! Roger