Microsoft KB Archive/248087

From BetaArchive Wiki
Knowledge Base

PRB: Visual Studio Error "Attempting to use invalid help file"

Article ID: 248087

Article Last Modified on 8/15/2005


  • MSDN 2003 Universal Edition
  • Microsoft Visual Studio 6.0 Enterprise Edition

This article was previously published under Q248087


When accessing Help in any Visual Studio 6.0 product, the following message appears:

Attempting to use an invalid help file.

When starting the MSDN Library from the Start menu, the following message appears:

Cannot open the file 'MSDN*.COL'

Where '*' correlates to the version of the MSDN Library. For example, the file would be MSDNVS6A.col for the MSDN Library that shipped with Visual Studio 6.0.


The file HHCOLREG.dat is either missing, corrupted, or contains outdated information. HHCOLREG.dat is located in the %WINDIR%\Help folder. By default this is C:\Windows\Help on Windows 95/98 and C:\WINNT\Help on Windows NT. On Windows 2000 there may also be an HHCOLREG.dat file in each user's profile directory.


First, verify that you can view hidden files:

  1. Open Windows Explorer.
  2. From the View menu, choose Folder Options. For Windows 2000 and Internet Explorer 5.0, Folder Options is listed on the Tools menu.
  3. Select the View tab in the Folder Options dialog box.
  4. Select the Show hidden files and folders option.

Next, rename the file HHCOLREG.dat to HHCOLREG.old and reinstall the MSDN Library. If this does not resolve the issue, a manual uninstall of the MSDN library will be necessary. For more information on how to manually uninstall the MSDN Library, see the following article in the Microsoft Knowledge Base:

240350 HOWTO: Manually Uninstall the MSDN Library


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

216109 HOWTO: Troubleshoot MSDN Library Run-Time/Install/Uninstall Problems

240350 HOWTO: Manually Uninstall the MSDN Library

Keywords: kbprb KB248087