Types of User Profiles

A user profile is a collection of folders and registry data that describes a user's environment when the user logs on to a client computer. Specifically, user profiles contain:

• A folder hierarchy that stores desktop icons, shortcut links, startup applications, and other data and settings. The structure of this folder hierarchy is discussed further in the section titled "User Profile Namespace in Windows Vista and Windows 7" later in this tutorial.
• A registry hive that stores user-defined desktop settings, application settings, persistent network connections, printer connections, and so on. The registry hive for a user profile, which is the Ntuser.dat file in the root of the user's profile folder, is mapped to the HKEY_CURRENT_USER portion of the registry when the user logs on. Ntuser.dat (a system file located in the root of the user's profile folder) maintains the user environment preferences when the user is logged on to the computer.

Windows clients support two kinds of user profiles:

• Local user profiles Local user profiles are stored on the client computer. When a user logs on to a Windows computer for the first time, a local user profile is created for the user and stored by default on %SystemDrive% inside the \Users\user_name folder on Windows Vista and later versions and in the \Documents And Settings\user_name folder on previous versions of Windows. Whenever the user logs on to the computer, the user's local user profile is loaded and the user's desktop environment is configured according to the data and settings stored in this profile. When the user logs off the computer, any configuration changes made to the user's desktop environment are saved in the user's profile when the profile unloads.
  All Windows computers support local user profiles by default, and the advantage of local user profiles is that they maintain the unique desktop environment of each user who logs on to the computer. Local user profiles thus enable several users to share the same computer while keeping their own user settings and data. The disadvantage of local user profiles is that they are local to the computer. This means that when the user logs on to a different computer, the user's data and settings do not follow her. This makes it difficult for users to roam, or use any available computer, in an enterprise environment.
• Roaming user profiles Roaming user profiles are stored in a central location on the network, which is generally a shared folder on a file server. When the user logs on to a client computer, the roaming user profile is downloaded from the network location and loaded onto the client computer to configure the user's desktop environment. When the user logs off the computer, any configuration changes made to the user's desktop are saved to the network share. In addition to maintaining a copy of the roaming profile on the network share, Windows also keeps a locally cached copy of the roaming profile on each computer to which the user logs on.
  Roaming user profiles are supported only in Active Directory Domain Services (AD DS) environments and must be deployed and configured appropriately. An advantage of roaming user profiles is that they allow a user to log on to any available computer on the network, download her profile, load the profile, and experience her unique desktop environment. Another advantage of roaming profiles is that they can be assigned to individual users or to groups of users, which provides flexibility in how desktop environments are deployed. The Windows XP implementation of RUP has several disadvantages that have been improved, first in Windows Vista and later with additional improvements in Windows 7. The section titled "Understanding Roaming User Profiles and Folder Redirection" later in this tutorial discusses these disadvantages and enhancements.
  Mandatory user profiles and super-mandatory user profiles are two variations of roaming user profiles. Mandatory user profiles are read-only versions of roaming user profiles that have been preconfigured to provide a consistent desktop environment that the user cannot modify. When a user account is configured to use a mandatory user profile, the user downloads the profile from the network share during logon. When the user logs off, any changes made to the user's desktop environment are not uploaded to the profile stored on a network location, and the changes made are overwritten during the next logon when the roaming profile is downloaded from the server. Supermandatory user profiles have these same characteristics of mandatory user profiles: They are read-only and are not copied back to the network during logoff. What makes them different, however, is that super-mandatory profiles are required for the user to log on. Any condition that prevents the super-mandatory user profile from loading also prevents the user from logging on to the computer. Therefore, super-mandatory user profiles should be used only in environments in which the network infrastructure is very reliable and the presence of the user profile is critical.

User Profiles for Service Accounts

In Windows Vista and later versions, special identities that are used for service accounts-such as Local System, Local Service, and Network Service-also have user profiles. The profiles for these accounts are located as follows:

• LocalSystem %WinDir%\System32\config\systemprofile
• LocalService %WinDir%\ServiceProfiles\LocalService
• NetworkService %WinDir%\ServiceProfiles\NetworkService