DOCUMENT:Q248087  11-JUN-2002  [msdn]
TITLE   :PRB: Visual Studio Error "Attempting to use invalid help file"
PRODUCT :Microsoft Developer Network
PROD/VER::6.0
OPER/SYS:
KEYWORDS:kbHTMLHelp kbMSDN kbVS600 kbDSupport

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The information in this article applies to:

 - Microsoft Developer Network (MSDN) 
 - Microsoft Visual Studio 6.0 
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SYMPTOMS
========

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.

CAUSE
=====

The file HHCOLREG.dat is either missing, corrupted, or contains outdated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.


RESOLUTION
==========

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:

   Q240350 HOWTO: Manually Uninstall the MSDN Library

REFERENCES
==========

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

   Q216109 HOWTO: Troubleshoot MSDN Library Run-Time/Install/Uninstall Problems

   Q240350 HOWTO: Manually Uninstall the MSDN Library

Additional query words:

======================================================================
Keywords          : kbHTMLHelp kbMSDN kbVS600 kbDSupport 
Technology        : kbVSsearch kbAudDeveloper kbMSDNSearch kbZNotKeyword2 kbVS600 kbVS600Search
Version           : :6.0
Issue type        : kbprb

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