In the master UV account, check if there's a user or accounts file. It's 
been too long ago for me to remember, but do you have a UV account in 
the user's home directory? Do you have something in UV that tells it 
what default account they should be logged into?
I'm too used to the Pr1me/Unix model where most/all people have a UV 
account in their home directory.
I can try and find my UV 9.6 or 10 documentation CDs, and find any 
Windows documentation (that assuming I can lay my hands on a working CD 
drive ...)
I have some nasty feeling that on occasion I had to edit the registry ...
Cheers,
Wol