Leia Sobre os perfis de usuário :
A user profile consists of the following elements:
- A registry hive. The registry hive is the file NTuser.dat. The hive is loaded by the system at user logon, and it is mapped to the HKEY_CURRENT_USER registry key. The user's registry hive maintains the user's registry-based preferences and configuration.
- A set of profile folders stored in the file system. User-profile files are stored in the Profiles directory, on a folder per-user basis. The user-profile folder is a container for applications and other system components to populate with sub-folders, and per-user data such as documents and configuration files. Windows Explorer uses the user-profile folders extensively for such items as the user's Desktop, Start menu and Documents folder.
Preste atenção em Perfis de usuários locais e na explicação Perfis de usuários móveis mencionados aqui.