PRB: Explorer Bar Does Not Appear in Internet Explorer 5.01 (247705)

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:

256986 Description of the Microsoft Windows Registry

SYMPTOMS

Beginning with Internet Explorer 5.01, if an Explorer Bar is installed along with a toolbar button (to activate it), the button may not function correctly in any new instances of the browser. Additionally, attempts to programmatically display the bar using IWebBrowser2::ShowBrowserBar may fail. The only way to display the bar is by using the Explorer Bar command on the View menu.

CAUSE

Initially, Internet Explorer retrieves an enumeration of the registered Explorer Bar objects from the registry using the component categories. To increase performance, it then caches this enumeration, causing subsequently added Explorer Bars to be overlooked.

RESOLUTION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To force Internet Explorer to rebuild the cache and recognize a new Explorer Bar, delete the following registry keys during the registration of the new Explorer Bar:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{00021493-0000-0000-C000-000000000046}\Enum

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{00021494-0000-0000-C000-000000000046}\Enum

NOTE: In versions of Internet Explorer prior to Internet Explorer 5.01, the HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable key did not exist. The Explorer Bar's self-registration code must be able to handle such a case.

REFERENCES

MSDN Online Web Workshop sites:

Creating Custom Explorer Bars, Tool Bands, and Desk Bands
http://msdn.microsoft.com/workshop/browser/ext/overview/bands.asp

Adding Explorer Bars
http://msdn.microsoft.com/workshop/browser/ext/tutorials/explorer.asp

Adding Toolbar Buttons
http://msdn.microsoft.com/workshop/browser/ext/tutorials/button.asp

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

214842 PRB: Installed DeskBand Not Displayed in Taskbar Shortcut Menu