A custom help option that uses a fully qualified domain name does not work in Communicator 2005

Consider the following scenario:

• An administrator creates a custom help option in Microsoft Office Communicator 2005 that uses a URL that contains a fully qualified domain name (FQDN).
• The help URL is not included in the Trusted sites zone on the Security tab of the Internet Options dialog box.
• The help URL is included in the Exceptions list in the Proxy Settings dialog box in Internet Explorer.

In this scenario, you experience the following symptoms:

• If you click the custom help option in Communicator 2005, nothing happens. The Web browser program does not start, and you do not receive an error message.
• If you start Help in Communicator 2005 before you click the custom help option, the custom help option starts the Web browser as expected, and the custom help content appears.

This problem occurs because the Communicator 2005 security manager cache does not include the sites that are listed in the Proxy Exception list. Therefore, the custom help URL is mapped to the Internet security zone. Therefore, the custom help option is not able to start successfully. If the built-in Help program is started before you start the custom help, the Web browser program populates the Security Manager cache. In this situation, later attempts to start the custom help option are successful.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To resolve this problem, a hotfix has been created that allows for the use of a new registry entry that you can use to bypass the process that maps the URL to a security zone. This functionality lets you have an implied trust of the custom help URL.

How to obtain the hotfix

This issue is fixed in the Communicator 2005 Hotfix Package dated February 16, 2007. For more information, click the following article number to view the article in the Microsoft Knowledge Base: To enable this hotfix, follow these steps:

1. Quit Communicator 2005.
2. Click Start, click Run, type regedit, and then click OK.
3. Locate and then click to select the following registry key:
   HKEY_CURRENT_USER\Software\Policies\Microsoft\Communicator
4. After you select the key that is specified in step 3, point to New on the Edit menu, and then click DWORD Value.
5. Type DisableHelpMenuSiteCheck, and then press ENTER.
6. Right-click DisableHelpMenuSiteCheck, and then click Modify.
7. In the Value data box, type 1, and then click OK.
8. On the File menu, click Exit to quit Registry Editor.

After you configure this registry entry, you must restart Communicator 2005. This registry value is read when Communicator 2005 starts.

To work around this problem, use one of the following methods:

• In the custom help URL, use the host name of the Web server instead of the FQDN of the Web server. For example, configure a URL that resembles the following:
  http://InternalHelp/Help.htm
• Add the custom help site to the Trusted sites zone on the Security tab of the Internet Options dialog box.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.