NT4 Server Username info file!!

Where might I find in Nt4 server, my username info? I had a bad drive and had to rebuild my server. It would be nice to find my old info on my old drive. My BDC failed for some reason.
I have moved all the user Profiles to the new drive and also all the users home folders, to the same locations on the new drive but I need to enter all the usernames.
Any ideas?

Thanks
Merv