The IDE does not open and you receive a "Cannot start program" error message when you try to start Visual Studio .NET or Visual Studio 2005 (891399)


The information in this article applies to:

  • Microsoft Visual Studio 2005 Professional Edition
  • Microsoft Visual Studio 2005 Standard Edition
  • Microsoft Visual Studio .NET (2003), Enterprise Architect Edition
  • Microsoft Visual Studio .NET (2003), Enterprise Developer Edition
  • Microsoft Visual Studio .NET (2003), Academic Edition
  • Microsoft Visual Studio .NET (2002), Professional Edition
  • Microsoft Visual Studio .NET (2002), Enterprise Architect Edition
  • Microsoft Visual Studio .NET (2002), Enterprise Developer Edition
  • Microsoft Visual Studio .NET (2002), Academic Edition
Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry

SYMPTOMS

When you try to start Microsoft Visual Studio .NET or Microsoft Visual Studio 2005, the IDE does not open. You may also receive the following error message:
Unexpected critical error; cannot start program
Sometimes, a Windows Installer message box may also incorrectly appear.

CAUSE

This problem occurs when the following conditions are true:
  • The Mso.dll file is corrupted. Mso.dll is a shared Microsoft Office file.
  • The last Microsoft Office program that was installed is trying to repair the Mso.dll file.

RESOLUTION

To resolve this problem, stop the pending repair of the Mso.dll file, delete the Mso.dll file, and then replace the file. To do this, follow these steps.

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 your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
  1. Click Start, click Run, type regedit, and then click OK.
  2. In Registry Editor, locate and then click the following registry subkey:

    HKEY_CLASSES_ROOT\TypeLib\{2DF8D04C-5BFA-101B-BDE5-00AA0044DE52}\2.2\0\win32

  3. Note the location of the folder that is specified for the Mso.dll file in the entry for this subkey. Typically, the Mso.dll file is located in the \Program Files\Common Files\Microsoft Shared\OFFICE11 folder.
  4. Make sure that the Mso.dll file is the only entry in this subkey. If there are other entries in this subkey, contact Microsoft Product Support Services to determine whether you can delete this subkey.
  5. On the Edit menu, click Delete.
  6. Click Yes to confirm the deletion.
  7. Locate the Mso.dll file in the folder that you noted in step 3.
  8. Right-click the Mso.dll file, and then click Delete.
  9. Click Yes to confirm that you want to send Mso.dll to the Recycle Bin.
  10. Reinstall Visual Studio .NET or Visual Studio 2005.

MORE INFORMATION

For additional information about how to install Visual Studio .NET, click the following article number to view the article in the Microsoft Knowledge Base:

319714 How to troubleshoot Visual Studio .NET installation

For additional information about similar problems, click the following article numbers to view the articles in the Microsoft Knowledge Base:

327062 "The application cannot start" error message when you try to run the MSDN Help Viewer

839548 "The application cannot start" error message when you start Visual Studio .NET on Windows Server 2003

Modification Type:MajorLast Reviewed:3/7/2006
Keywords:kbvs2005swept kbvs2005applies kbtshoot kbprb KB891399 kbAudDeveloper kbAudITPRO
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