A nested hierarchy of subkeys contains the settings for the environment of the current logged-on user. Almost all of the configuration settings that are recorded here are changed via the GUI, not interactively in the registry.
AppEvents Continuing the tradition that started with Windows 9x, Microsoft dedicates an entire registry key to linking sounds to events. The key has two subkeys:
■ EventLabels A group of subkeys with names that are really labels for types of events. The data item in each key is a description of the label (and frequently the description matches the label exactly).
■ Schemes Contains additional subkeys that hold a variety of settings, including the actual names of the sound files that are linked to events.
Users link sound files to events in the Sounds and Audio Devices applet in Control Panel. In addition, some applications add schemes, sound files, and event descriptions (for example, AOL’s “You’ve Got Mail,” which comes to you from a company badly in need of grammar lessons, or the little tune that announces new mail in Eudora).
Console The Console key stores settings for the Windows Server 2003 console subsystem, which runs all character-based applications (including the Command Processor, which youuse for command-line work). See Chapter 7 for information about setting configuration options for the command window.
Control Panel This key and its subkeys contain settings that control the appearance of the desktop, along with user-defined options for many of the Control Panel applets.
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When youexpand the key, yousee subkey names that obviously match some of the applets, along with a number of other settings categories. The values of the data items change when users make changes to options in the Control Panel applets. Most of the options take effect immediately, without any need to restart the operating system.
Don’t be deceived by the notion that because these settings generally affect only the user interface, they’re harmless. Administrators who fall for that belief, and give users total freedom to alter default settings, are frequently sorry. Some of the settings in the Control Panel key and its subkeys are more powerful than they seem. For example, an inexperienced user who messes around with video settings can create enough damage to keep the computer from booting normally. A password-protected screen saver is important for a client machine that could have sensitive data on the screen, and a user who finds that feature annoying might disable it and then head for the coffee shop with your payroll records displayed on the monitor. And, of course, stories abound in the help desk community about users who enable the password-protected screen saver feature without bothering to write down or remember the password, and every time they leave their desks, the help desk can expect a call.
Windows Server 2003 provides a full range of group policies to control access to the Control Panel applets (see Chapter 22 for specifics).
Environment This key contains data entries that represent environment variables settings for the logged-on user.
Both the Temp and Tmp environment variables are included because applications might use either terminology.
In addition to (or, even better, instead of) using the registry to work with these settings, you can view and modify the settings in the System Properties dialog (right- click My Computer and choose Properties). On the Advanced tab, click Environment Variables to see information similar to that shown in Figure 4-1.
If youmake changes to the environment settings, via either the registry or the System Properties dialog, the new settings don’t take effect until the next time the user logs on. Color profile: Generic CMYK printer profile
The data items in the Environment key must be REG_EXPAND_SZ data types. If you enter an item of a different type, or you change the existing data type, the system will not replace the variable with its value.
Identities This key, which doesn’t exist in previous versions of Windows, is undocumented by Microsoft. It seems to be an ID for the current user, but not the primary ID. In HKEY_USERS, each user has a unique ID. The current user’s unique ID key has a subkey that matches the value of this data item.
Keyboard Layout This subkey stores information about the installed keyboard layouts, including hardware and driver settings. In addition, if the user adds more keyboards (keyboard language files), information about those keyboards is maintained in the subkeys.
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Hardware and driver changes should be effected in the Keyboard applet in Control Panel. Additional keyboards are added in the Regional and Language Options applet.
Network This key only exists if the current user has mapped network drives. The key itself is a parent key and holds no important data. A child subkey exists for each persistent mapped drive, and the subkey is named for the drive letter to which the share is mapped.
If a user maps a drive and does not select the option Reconnect At Logon, the mapped drive is not written to the registry. (All currently mapped drives, regardless of the persistent state, have icons in My Computer.)
The default condition of the Reconnect At Logon option is whatever was selected the last time the user mapped a drive.
Each subkey holds information about its connection:
■ ConnectionType Specifies the type of connection for this mapping. A value of 1 means drive redirection; a value of 2 means printer redirection.
■ DeferFlags This key isn’t documented by Microsoft (although the documentation team tells me they hope to add information some time in the future). In my registry, all mapped drives have a value of 4. A value of 4 usually indicates a dependency on a specific set of circumstances, where 1 = one thing, 2 = something else, and so on. (If I ever figure it out, I’ll post the information at www.admin911.com.)
■ ProviderName Specifies the network provider that makes the connection. By default, Microsoft Windows Network is the value (which you can mentally translate as Microsoft LanMan).
■ ProviderType Identifies the provider used for the connection. The value is a constant assigned by Microsoft. For Microsoft LanMan, the constant is 0x20000 (open the data item to see the hex data). For third-party providers, the value is a constant assigned to the provider.
Color profile: Generic CMYK printer profile Composite Default screen
■ RemotePath The UNC to the mapped share.
■ UserName Specifies a username to be used for the connection. By default, this data item has no value, because most of the time, the user is the logged-on user. However, if the mapping configuration specifies a different username for connecting to this mapped drive, that username appears as the value for this data item. (The Map Network Drive Wizard has an option named Connect Using a Different User Name, which accepts a username and password for the connection that’s being configured.)
Printers This subkey contains information about the printers installed on the computer, including user-set configuration options.
Session Information This subkey seems to contain information about the applications in use in the current session (the only data item in my registry is ProgramCount, which has a value equal to the number of programs that are currently open). I use the word “seems” because it’s undocumented. Microsoft’s registry documentation team told me they hadn’t documented this key, but plan to in a future version of Windows.
Software This key stores application user settings and program variables that are specific to the logged-on user. The data items change as users make configuration changes. The subkeys under this key are not just created by software installation programs—the operating system keeps all sorts of important settings here. It’s beyond the scope of this book to engage in a detailed discussion of user settings.
UNICODE Program Groups This key exists for downlevel compatibility, for users who run Program Manager. The data items, if any exist, define the contents of all personal program groups in Program Manager.
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