About User Profiles

The system creates a user profile the first time that a user logs on to a computer. At subsequent logons, the system loads the user’s profile, and then other system components configure the user’s environment according to the information in the profile.

Types of User Profiles

• Local User Profiles. A local user profile is created the first time that a user logs on to a computer. The profile is stored on the computer’s local hard disk. Changes made to the local user profile are specific to the user and to the computer on which the changes are made.
• Roaming User Profiles. A roaming user profile is a copy of the local profile that is copied to, and stored on, a server share. This profile is downloaded to any computer that a user logs onto on a network. Changes made to a roaming user profile are synchronized with the server copy of the profile when the user logs off. The advantage of roaming user profiles is that users do not need to create a profile on each computer they use on a network.
• Mandatory User Profiles. A mandatory user profile is a type of profile that administrators can use to specify settings for users. Only system administrators can make changes to mandatory user profiles. Changes made by users to desktop settings are lost when the user logs off.
• Temporary User Profiles. A temporary profile is issued each time that an error condition prevents the user’s profile from loading. Temporary profiles are deleted at the end of each session, and changes made by the user to desktop settings and files are lost when the user logs off. Temporary profiles are only available on computers running WindowsВ 2000 and later.

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.

User profiles provide the following advantages:

• When the user logs on to a computer, the system uses the same settings that were in use when the user last logged off.
• When sharing a computer with other users, each user receives their customized desktop after logging on.
• Settings in the user profile are unique to each user. The settings cannot be accessed by other users. Changes made to one user’s profile do not affect other users or other users’ profiles.

User Profile Tiles in Windows 7 and Later

In WindowsВ 7 or later, each user profile has an associated image presented as a user tile. These tiles appear to users on the User Accounts Control Panel item and its Manage Accounts subpage.. The image files for the default Guest and default User accounts also appear here if you have Administrator access rights.

NoteВ В The Manage Accounts subpage is accessed through the Manage another account link in the User Accounts Control Panel item.

• %ProgramData%\Microsoft\User Account Pictures\Guest.bmp
• %ProgramData%\Microsoft\User Account Pictures\User.bmp

The user’s tile image is stored in the %SystemDrive%\Users\ \AppData\Local\Temp folder as .bmp. Any slash characters (\) are converted to plus sign characters (+). For example, DOMAIN\user is converted to DOMAIN+user.

The image file appears in the user’s Temp folder:

• After the user completes the initial system setup (OOBE).
• When the user first launches the User Accounts Control Panel item.
• When the user goes to the Manage Accounts subpage of the User Accounts Control Panel item. In addition, tiles for all other users on the computer are shown.

Those instances are the only times that the images are created or updated. Therefore, there are several caveats to keep in mind when using the Temp folder location programmatically:

The user’s tile is not guaranteed to be present. If the user deletes the .bmp file, for instance manually or through a utility that deletes temporary files, that user tile is not automatically recreated until the user launches the User Accounts Control Panel item or Manage Accounts subpage.

User tiles for other users on the computer might not be present in the currently logged-on user’s Temp folder. For example, if User A creates User B through the User Accounts Control Panel item, User B’s tile is created in User A’s Temp folder when Windows sends User A to the Manage Accounts subpage. Because the directory structure is not created for User B until he or she logs on, User A’s Temp folder is the only location that User B’s tile is stored. When User B logs on, the only image stored in User B’s Temp folder is his or her own.

1. To get all user tiles for users on a system, applications might need to search in each user’s Temp directory.
2. Because the access control list (ACL) of these Temp directories allows access to SYSTEM, Administrator, and the current user, applications need to elevate to access for other users.

Other users’ tiles are not guaranteed to be up-to-date in their Temp folders. If User B updates his or her user tile, User A will not see the change until User A accesses the Manage Accounts subpage. Therefore, if applications use User A’s Temp folder to obtain User B’s tile, those applications can get an out-of-date image file.

File Types

This topic explains how to create new file types and how to associate your app with your file type and other well-defined file types. Files with a shared common file name extension (.doc, .html, and so on) are of the same type. For example, if you create a new text editor, then you can use the existing .txt file type. In other cases, you might need to create a new file type.

This topic is organized as follows:

Additional information can be found on the following topics:

Public and Private File Types

Public file types are also known as popular or contentious types because competing applications might want to be associated with these file types. Characteristics of public file types include:

• They are typically defined by standards bodies, and/or are promoted by their defining organizations as interchange formats.
• They are often exchanged between computers and users for diverse purposes.
• They need to be supported on many different platforms.
• Applications from multiple vendors are likely to handle them.

Some examples of file types that are considered public are the image file types .png, .gif, .jpg, and .bmp, and the audio types .wav, .mp3, and .au.

Unlike public file types, private or proprietary file types typically have a format that is implemented and understood by only one application or vendor. As a result, private file types are typically not prone to conflicts between applications. Some file types can start as private file types but later become public file types.

Windows does not differentiate between public and private file types. The distinction is relevant only in making decisions about your choice of file type registration.

Registering a File Type

To associate the file type with an existing application, locate the application ProgID in the registry. To associate the file type with a new application, define a ProgID for your application. For information about defining a new ProgID, see Programmatic Identifiers.

File name extension subkeys have the following general form: extension=ProgID. File name extension subkeys are stored in the HKEY_CLASSES_ROOT subtree.

It is important to include the leading period (.) when creating file type subkeys in the registry. For example, if you want a file type with the short extension .myp and the long extension .myp-file to be opened with an application called MyProgram, use the following syntax:

As demonstrated in the preceding example, if you also register a short file name extension (.myp), you should create a subkey for the long extension (.myp-file) as well. For more information, see File Type Handlers.

Setting Optional Subkeys and File Type Extension Attributes

File type extension entries in the registry have several optional subkeys and attributes.

The file type extension entries that are used by file associations are described in the following table. All values are of the REG_SZ type.

Registry entry	Action
Default	Set the default value of the extension subkey to the ProgID to which it is linked.
Content Type	Set the Content Type value to the file type’s MIME content type.
OpenWithList	Do not use. This subkey contains one or more application subkeys for applications that appear in the Open with dialog box entry for the file type and is intended only for .exe applications on operating systems prior to WindowsВ XP. Use OpenWithProgIds instead.
OpenWithProgIds	This subkey contains a list of alternate ProgIDs for this file type. The programs for these ProgIDs appear in the Open with menu and are available as default Windows Store apps for the file type. Whenever an application takes over this file type by changing the default value, it should also add an entry to this list.
PerceivedType	Set the PerceivedType value to the PerceivedType to which the file belongs, if any. This string is not used by Windows versions prior to WindowsВ Vista. For more information, see Perceived Types and Application Registration.

The general form of a file name extension subkey is as follows. All entry types are of the REG_SZ type.

Important considerations about file types include:

The HKEY_CLASSES_ROOT subtree is a view formed by merging HKEY_CURRENT_USER\Software\Classes and HKEY_LOCAL_MACHINE\Software\Classes

In general, HKEY_CLASSES_ROOT is intended to be read from but not written to. For more information, see the HKEY_CLASSES_ROOT article.

To register a file type globally on a particular computer, create an entry for the file type in the HKEY_LOCAL_MACHINE\Software\Classes subkey.

To make a file type registration visible to the current user only, create an entry for the file type in the HKEY_CURRENT_USER\Software\Classes subkey.

An application can provide its own implementation of a verb, such as open or play, as shown in the following registry example.

Subkeys of the verb subkey include the command line and the drop target method: command and DropTarget.

When you create or change a file association, it is important to notify the system that you have made a change. Do so by calling SHChangeNotify and specifying the SHCNE_ASSOCCHANGED event. If you do not call SHChangeNotify, the change may not be recognized until after the system is rebooted.

To retrieve registry information regarding a file association, use the IQueryAssociations interface. For a scenario that illustrates this procedure, see File Association Sample Scenario.

Both the App Paths and Applications registry subkeys are used to register and control the behavior of the system on behalf of applications. For more detailed information about this functionality, see Application Registration.

Deleting Registry Information During Uninstallation

When uninstalling an application, the ProgIDs and most other registry information associated with that application should be deleted as part of the uninstallation. However, applications that have taken ownership of a file type (by setting the Default value of the file type’s HKEY_CLASSES_ROOT\.extension subkey to the ProgID of the application) should not attempt to remove that value when uninstalling. Leaving the data in place for the Default value avoids the difficulty of determining whether another application has taken ownership of the file type and overwritten the Default value after the original application was installed. Windows respects the Default value only if the ProgID found there is a registered ProgID. If the ProgID is unregistered, it is ignored.

Note that other file-type ownership information is stored in the HKEY_CURRENT_USERsubtree and also is used only when the application that it references is registered. Therefore, this data does not need to be removed when uninstalling an application.

As an example, the following shows the state of the registry before an application is uninstalled:

The following shows the state of those same registry entries after the application has been uninstalled.

File Types That Support Open Metadata

In WindowsВ 7 and later, the following file types support open metadata.

File Types and File Associations

This section on file types and file associations is organized as follows:

Additional Resources

• Set Program Access and Computer Defaults (SPAD) is a Windows Control Panel which allows users with administrative privilege to set a machine default and hide or show an application. Media, Mail, Browser, Messenger and Java applications are examples of applications registered in SPAD. Set Your Default Programs (SYDP) is a Windows Control Panel, that works with limited privileges, and permits users to set a user default. Any application can register in SYDP. For information about SPAD and SYDP application registration, see Guidelines for File Associations and Default Programs, and Set Program Access and Computer Defaults (SPAD).
• For related conceptual background, see Overview of Verbs and File Associations.
• To create a Shell data store, see Implementing the Basic Folder Object Interfaces.

For related reference documentation, see the following topics:

• To execute a verb on a Shell item, see the InvokeVerb method.
• To retrieve a collection of verbs that can be executed on a Shell item, see the Verbs method.
• For performing an operation on a specified file, see either the ShellExecute or ShellExecuteEx functions.
• For a list of default perceived types, see the PERCEIVED enumeration.
• To retrieves a file’s perceived type based on its extension, see the AssocGetPerceivedType function.