Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base: NoteThe registry in 64-bit versions of Windows XP and Windows Server 2003 is divided into 32-bit and 64-bit subkeys. Many of the 32-bit subkeys have the same names as their 64-bit counterparts, and vice versa. The default 64-bit version of Registry Editor that is included with 64-bit versions of Windows XP and Windows Server 2003 displays the 32-bit subkeys in the following registry subkey, or "hive": For additional information about how to view the registry on 64-bit versions of Windows, click the following article number to view the article in the Microsoft Knowledge Base:

Back up the registry

Before you edit the registry, export the keys in the registry that you plan to edit, or back up the whole registry. If a problem occurs, you can then follow the steps in the Restore the registry section of this article to restore the registry to its previous state.

Export registry subkeys

You can follow these steps to export a registry subkey before you edit it.

Note Do not follow these steps to export a whole registry subtree. (HKEY_CURRENT_USER is an example of such a subtree.) If you must back up whole registry subtrees, back up the whole registry instead.

1.	Click Start, and then click Run.
2.	In the Open box, type regedit, and then click OK.
3.	Locate and then click the subkey that contains the value that you want to edit.
4.	On the File menu, click Export.
5.	In the Save in box, select a location where you want to save the Registration Entries (.reg) file, type a file name in the File name box, and then click Save.

Back up the whole registry

To back up the whole registry, use the Backup utility to back up the system state. The system state includes the registry, the COM+ Class Registration Database, and your boot files. For additional information about using the Backup utility to back up the system state, click the following article numbers to view the articles in the Microsoft Knowledge Base:

Edit the registry

Use the Windows user interface

We recommend that you use the Windows user interface to change your system settings instead of manually editing the registry. However, editing the registry may sometimes be the best method to resolve a product issue. If the issue is documented in the Microsoft Knowledge Base, an article with step-by-step instructions to edit the registry for that issue will be available. We recommend that you follow these instructions very exactly.

Use Registry Editor

Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems that result from incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

Editing the registry involves the following six types of procedures:

•	Locating a subtree, key, subkey, or value
•	Adding a subkey
•	Adding a value
•	Changing a value
•	Deleting a subkey or a value
•	Renaming a subkey or a value

Locating a subtree, key, subkey, or value

There are five top-level registry subtreesEach of them starts with "HKEY." In the following example, HKEY_LOCAL_MACHINE is the subtree, SOFTWARE is the key, and Microsoft is the subkey. In Registry Editor, you can search through the keys and subkeys in the same way that you search through your folders in Windows Explorer.

The keys and the subkeys are listed in a folder tree in the left pane of Registry Editor. If you click a key or a subkey in the left pane, information about the value name, the value type, and the value data appears in the right pane.

As in Windows Explorer, each folder may be expanded by clicking the plus sign (+) that is next to it. After a folder is expanded, the plus sign changes to a minus sign (-).

Note When this article says to expand an item, click the plus sign next to that item.

To locate the Microsoftsubkey that is mentioned earlier in this section, follow these steps:

1.	Click Start, click Run, type regedit, and then click OK.
2.	Expand HKEY_LOCAL_MACHINE.
3.	Expand SOFTWARE.
4.	Click Microsoft. Note When you click the Microsoft subkey, its values appear in the right pane. To view the next lower level of subkeys, expand the Microsoft subkey. To locate a value, click the subkey that contains the value, and then view the contents of the right pane.

Adding a key

To add a new subkey named TestSubkey to the Microsoft subkey, follow these steps:

1.	Expand HKEY_LOCAL_MACHINE.
2.	Expand SOFTWARE.
3.	Click the Microsoft subkey.
4.	On the Edit menu, point to New, and then click Key.
5.	Type TestSubkey, and then press ENTER.

Adding a value

To add a new DWORD Value named TestDWORD and to set its value data to 1 in the TestSubkey key, follow these steps:

1.	Expand HKEY_LOCAL_MACHINE.
2.	Expand SOFTWARE.
3.	Expand Microsoft.
4.	Click the TestSubkey subkey.
5.	On the Edit menu, point to New, and then click DWORD Value.
6.	Type TestDWORD and then press ENTER..
7.	Right-click the TestDWORD DWORD Value, and then click Modify.
8.	Type 1, and then click OK.

Changing a value

To change the value data for the TestDWORD DWORD Value to 0 in the TestSubkey key, follow these steps:

1.	Expand HKEY_LOCAL_MACHINE.
2.	Expand SOFTWARE.
3.	Expand Microsoft.
4.	Click the TestSubkey subkey.
5.	Right-click the TestDWORD DWORD Value, and then click Modify.
6.	Type 0, and then click OK.

Renaming a key or value

To rename the TestSubkeysubkey to Test, follow these steps:

1.	Expand HKEY_LOCAL_MACHINE.
2.	Expand SOFTWARE.
3.	Expand Microsoft.
4.	Right-click the TestSubkey key, and then click Rename.
5.	Type Test, and then press ENTER.

Deleting a key or value

To delete the TestDWORD DWORD Value in the TestSubkey subkey, follow these steps:

1.	Expand HKEY_LOCAL_MACHINE.
2.	Expand SOFTWARE.
3.	Expand Microsoft.
4.	Click the TestSubkey subkey.
5.	Right-click the TestDWORD DWORD Value, and then click Delete.
6.	Click Yes to confirm that you want to delete the value.

For more information about editing the registry, follow these steps in Registry Editor:

1.	On the Help menu, click Help Topics.
2.	On the Contents tab, double-click Registry Editor.
3.	Double-click How To.
4.	Double-click Change Keys and Values, and then click the topic that you want.

Use Group Policy

Microsoft Management Console (MMC) hosts administrative tools that you can use to administer networks, computers, services, and other system components. The Group Policy MMC snap-in allows administrators to define policy settings that are applied to computers or users. You can implement Group Policy on local computers by using the local Group Policy MMC snap-in, Gpedit.msc. You can implement Group Policy in Active Directory by using the Active Directory Users and Computers MMC snap-in. For additional information about using Group Policy, see the Help topics in the appropriate Group Policy MMC snap-in.

Use a Registration Entries (.reg) file

Create a Registration Entries (.reg) file that contains the registry changes, and then run the .reg file on the computer where you want to make the changes. You can run the .reg file manually or by using a logon script. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Use Windows Scripting Host

The Windows Scripting Host lets you run VBScript and JScript scripts directly in the operating system. You can create VBScript and JScript files that use Windows Scripting Host methods to delete, to read, and to write registry keys and values. For additional information about these methods, visit the following Microsoft Web sites:

Use Windows Management Instrumentation

Windows Management Instrumentation (WMI) is a component of the Microsoft Windows operating system and is the Microsoft implementation of Web-Based Enterprise Management (WBEM). WBEM is an industry initiative to develop a standard technology for accessing management information in an enterprise environment. You can use WMI to automate administrative tasks (such as editing the registry) in an enterprise environment. You can use WMI in scripting languages that have an engine on Windows and that handle Microsoft ActiveX objects. You can also use the WMI Command-Line utility (Wmic.exe) to modify the Windows registry.

For additional information about WMI, visit the following Microsoft Web site: For additional information about the Wmic.exe, click the following article number to view the article in the Microsoft Knowledge Base:

Use Console Registry Tool for Windows

You can use the Console Registry Tool for Windows (Reg.exe) to edit the registry. For help with the Reg.exe tool, type reg /? at the Command Prompt, and then click OK.

Restore the registry

To restore the registry, use the appropriate method.

Restore the registry keys

To restore registry subkeys that you exported, double-click the Registration Entries (.reg) file that you saved in the Export registry subkeys section. Alternatively, you can restore the whole registry from a backup. For additional information about how to restore the whole registry, see the Restore the whole registry section.

Restore the whole registry

To restore the whole registry, restore the system state from a backup. For additional information about how to restore the system state from a backup, click the following article number to view the article in the Microsoft Knowledge Base: Note Backing up the system state also creates updated copies of the registry files in the %SystemRoot%\Repair folder. If you cannot start Windows XP after you edit the registry, you can replace the registry files manually by using the steps in the "Part One" section of the following Microsoft Knowledge Base article: