I have encountered a site where a number of Windows 7 computers don't display ANY users in the
Manage Accounts / Choose the account you would like to change
The users do show up in Computer Management /... / Users and "Account is disabled" is NOT checked.
The users do show up as icons in the logon screen.
A system restore to a previous restore point seemed to work but briefly.
I have tried using the regedit to create SpecialAccounts, etc. but that didn't seem to help either....