Removal of application mappings may cause an HTTP 404 error in Outlook Web Access

When you log on to your mailbox by using Microsoft Outlook Web Access, you may experience one or more of the following symptoms:

• You receive the following error message:
  HTTP 404 File Not Found
• A directory listing of drive M is displayed.
• You receive an 80004005 error when you try to expand the public folder tree in Exchange System Manager.

This issue may occur after you have used a workaround that is documented in the frequently asked questions (FAQ) section of Microsoft Security Bulletin MS01-023. In this case, you may have selected an option that overrides the application mappings of the Exchange virtual directory, the Public virtual directory, and the Exadmin virtual directory with the application mappings of the Default Web Site. This behavior removes the application mappings for Davex.dll on back-end servers and on stand-alone servers and removes the application mappings for Exprox.dll on front-end servers.

To resolve this issue, use one of the following methods.

Method 1

Restart the Microsoft Exchange System Attendant. This causes the directory service-to-metabase (DS2MB) process to replicate the appropriate Active Directory information to the metabase, including the application mappings for Davex.dll and Exprox.dll.

Note When you restart the System Attendant, the configuration settings of the Exchange-related virtual directories in the Internet Services Manager are overwritten with the configuration settings that are configured in Exchange System Manager.

Method 2

If the issue still occurs after you restart the System Attendant, use MetaEdit to delete the DS2MB subkey from the metabase, and then restart the System Attendant. This action re-creates the DS2MB key. When the DS2MB subkey is re-created, the correct mappings for the Exchange virtual directories are also re-created.

For more information about how to install MetaEdit on Microsoft Windows NT Server 4.0, click the following article number to view the article in the Microsoft Knowledge Base:

Edit the metabase

To edit the metabase, follow these steps.

Warning If you edit the metabase incorrectly, you can cause serious problems that may require that you reinstall any product that uses the metabase. Microsoft cannot guarantee that problems that result if you incorrectly edit the metabase can be solved. Edit the metabase at your own risk.

Note Always back up the metabase before you edit it.

1. Click Start, point to Programs, point to Administrative Tools, and then click Services.
2. Right-click Microsoft Exchange System Attendant, and then click Stop.
3. When you are prompted, click Yes to stop the other services.
4. Click Start, point to Programs, point to Administrative Tools, and then click MetaEdit 2.2.
5. Locate the LM\DS2MB subkey in the metabase.
6. On the File menu, click Export text file, and then click Yes.
7. Type a name for the file, click Save, and then click Yes in the confirmation dialog box.
8. Click OK.
9. Right-click the LM\DS2MB subkey, click Delete, and then click Yes to confirm the deletion.
10. Quit MetaEdit.

Restart the administrative services

To restart the administrative services, follow these steps:

1. Click Start, point to Programs, point to Administrative Tools, and then click Services.
2. Right-click IIS Admin Service, and then click Restart.
3. Click Yes.
4. Right-click Microsoft Exchange System Attendant, and then click Start.
5. Right-click Microsoft Exchange MTA Stacks, and then click Start.
6. Right-click Microsoft Exchange Information Store, and then click Start.

Method 3

If this issue still occurs after you manually delete the DS2MB subkey from the metabase , manually delete the Exchange virtual directory, the Public virtual directory, and the Exadmin virtual directory in Internet Services Manager, and then restart the Microsoft Exchange System Attendant.

For additional information about how to delete the Exchange virtual directories, click the following article number to view the article in the Microsoft Knowledge Base:

To view Microsoft Security Bulletin MS01-023, visit the following Microsoft Web site: The frequently asked questions (FAQ) section of this security bulletin contains the following question: The best way to protect your Web server is to install the update. However, if you cannot install the update for some reason, you can help protect your server by disabling Internet Printing.

For more information about how to disable Internet Printing, visit the following Microsoft Web site: To disable Internet Printing, follow these steps:

1. Click Start, click Run, type MMC, and then click OK to open Group Policy.
2. Click Console, and then click Add/Remove Snap-in.
3. Click Add, click Group Policy, click Add, and then click Finish.
4. Click Close, and then click OK.
5. Expand Local Computer Policy, click Computer Configuration, click Administrative Templates, and then click Printers.
6. Double-click Web-based Printing, select Disabled, and then click OK.
7. Close Group Policy.
   
   Note If the server is part of a domain, make sure that Web-based Printing is also disabled in the domain policy settings.

For additional information about the IIS Lockdown tool or the URLscan tool and Exchange 2000, click the following article number to view the article in the Microsoft Knowledge Base: