How to manage Internet Explorer add-ons in Windows XP Service Pack 2

Microsoft Internet Explorer add-ons are software components. When you visit a Web site, Internet Explorer add-ons may be downloaded automatically, or you may be prompted to download an add-on. For some add-ons, you might specifically visit a Web site to obtain the latest add-on for Internet Explorer. These components may be third-party ActiveX controls that extend browser functionality or that provide special user interface elements in Internet Explorer. You can control add-ons by using the Manage Add-ons feature. This article describes how to use and how to troubleshoot this feature.

To make sure that the Manage Add-Ons dialog box is displaying as many add-ons as possible, update the Add-on Manager. To update the Add-on Manager, visit the following Microsoft Web sites:

Using the Manage Add-ons feature

To change the status of an add-on or to update an add-on, follow these steps:

1. Start Internet Explorer.
2. On the Tools menu, click Manage Add-ons.
3. Click the name of the add-on.
4. Use one of the following methods:
   • Click Update ActiveX to replace the add-on with the current version. This option is not available for all add-ons.
   • To enable an add-on, click Enable, and then click OK.
   • To disable an add-on, click Disable, and then click OK.

You may have to restart Internet Explorer for the changes to take effect after you enable or disable an add-on.

Troubleshooting add-ons

It is frequently acceptable to use add-ons from trusted sources. But sometimes add-ons cause Internet Explorer to quit unexpectedly. Internet Explorer may quit unexpectedly if the add-on was poorly designed or if the add-on was created for an earlier version of Internet Explorer. When Internet Explorer quits unexpectedly, you may be prompted to disable the add-on. If Internet Explorer quits unexpectedly, try one or more of the following:

• Try to update the add-on.
• Disable the add-on, and then visit the same Web site. Verify that you have to have the add-on for the Web site.
• If the features of the add-on are needed for a Web site, or if the features of the add-on enhance your browsing experience, enable the add-on.

When an add-on is blocked from installation because the publisher is blocked, the Manage Add-ons interface displays an additional category for add-ons that are blocked. When you visit a Web site, and that Web site uses an add-on that is blocked, you receive a notification in the status bar. The notification may indicate that some content cannot be displayed because one or more add-ons that are required are blocked. Or, the notification may indicate that an add-on that is required is disabled. You can enable a blocked add-on in the Manage Add-ons dialog box or in the notification in the status bar.

For more information about publishers that are blocked, follow these steps:

1. In Internet Explorer, click Help, and then click Contents and Index.
2. In the Help dialog box, click the Search tab, type blocked publisher, and then click List Topics.

You can use the Manage Add-ons feature to help troubleshoot other Internet Explorer issues that are frequently caused by third-party components. Add the Manage Add-ons feature to your troubleshooting practices.

Troubleshooting the Manage Add-ons feature

If you experience a problem when you use the Manage Add-ons feature, try the following:

• Log on to the computer as a different user, and then repeat the task. The configuration of disabled add-ons is stored on a per-user basis.
• Examine the following registry subkey for add-ons that are blocked:
  HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings
  Each add-on that is blocked or disabled is represented by a subkey that has the class identifier (CLSID) of the add-on that is blocked. You can search for the CLSID in the HKEY_CLASSES_ROOT registry key to determine the add-on that each key represents.
  
  Note The
  Settings
  registry subkey is not created until at least one add-on is blocked or disabled.

Managing add-ons by using registry entries and Group Policy

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
As an administrator, you can use Group Policy to predefine the controls that users can enable or disable. Use the Group Policy Object Editor to change the policy settings.

1. Click Start, click Run, type gpedit.msc, and then click OK.
2. Expand Computer Configuration or User Configuration, expand Administrative Templates, expand Windows Components, expand Internet Explorer, expand Security Features, and then click Add-on Management.

The following policy settings are available:

• Deny all add-ons unless specifically allowed in the Add-on List
• Add-on List
• Process List
• All Processes

Deny all add-ons unless specifically allowed in the Add-on List

You can configure each client to deny all the add-ons that are not included in the Add-on List policy setting by enabling the following policy setting:This policy setting prevents add-ons from being installed or from being used. This restriction also prevents the user from managing add-on policy settings individually. If you do not configure this policy setting, users can manage add-ons that are not already defined in the Add-on List.

Add-on List

You specify individual add-ons by using the CLSID in the Add-on List policy setting. The Value Name part of the policy setting must be the CLSID of the add-on, and the CLSID must include the braces that enclose the rest of the CLSID. The Value part of the policy setting must contain one of three possible values:

• 0 - The add-on is disabled, and users cannot manage the add-on from the user interface.
• 1 - The add-on is enabled, and users cannot manage the add-on from the user interface.
• 2 - The add-on is enabled, and users can manage the add-on from the user interface.

The list of add-ons that are contained in the Add-on List policy setting are stored in one of the following registry subkeys:

• HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID
• HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID

The subkey contains the CLSIDs of the individual add-ons as strings with the data.

Disabling all access to add-on management

To have us enable or disable the access to add-on management for you, go to the "Fix it for me" section. If you prefer to enable or disable the access to add-on management yourself, go to the "Let me fix it myself" section.

Fix it for me

To fix this problem automatically, click the Fix it button or link. In the File Download dialog box, click Run, and then follow the steps in the Fix it Wizard.




Notes

• This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
• If you are not on the computer that has the problem, save the Fix it solution to a flash drive or a CD, and then run it on the computer that has the problem.

Let me fix it myself

To turn off the Disable option and the Enable option for all add-ons, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate the following registry subkey:
   HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Internet Explorer\Restrictions
   
   Note This registry subkey is available only in a domain environment where access to add-on management is disabled through a group policy by an administrator.
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type NoExtensionManagement.
5. Double-click NoExtensionManagement, and then type 1.
   
   The following are the values that you can specify:
   • 0 - The user can enable or disable the add-ons.
   • 1 - The user cannot change the status of any add-ons.
6. Click OK, and then quit Registry Editor.

To set this registry entry as part of Group Policy, follow these steps:

1. In the Group Policy Object Editor, expand Computer Configuration or User Configuration.
2. Expand Administrative Templates, expand Windows Components, expand Internet Explorer, and then double-click the following policy setting:
   Do not allow users to enable or disable add-ons