PRB: "Unable to Display Help" or "No Help Available" Error Messages for ADO from Within Visual Basic (251147)


The information in this article applies to:

  • Microsoft Visual Basic Learning Edition for Windows 6.0
  • Microsoft Visual Basic Professional Edition for Windows 6.0
  • Microsoft Visual Basic Enterprise Edition for Windows 6.0
This article was previously published under Q251147

SYMPTOMS

When you try to access ActiveX Data Objects (ADO) documentation from within Visual Basic by pressing F1 from the code editor or from within the object browser, nothing occurs, or you receive one of the following error messages:
Unable to display help

-or-

No help available

CAUSE

This problem occurs because the following items must exist to access context-sensitive help for ADO in the Visual Basic IDE:
  • The correct version of the ADO compiled HTML help file that corresponds to the ADO version that is referenced in the project references. -and-

  • An entry in the registry that lists this ADO compiled HTML help file as an available HTML help file.
This problem is known to occur when one or both of these items are missing.

RESOLUTION

To resolve this problem, follow these steps:
  1. Make sure that you have the compiled HTML help file that corresponds to the ADO version that is referenced in your project references. This file is named ADO2?0.chm, where the question mark (?) represents the minor version number.

    For example, when you reference ADO 2.6 (which Microsoft Data Access Components 2.6 installs) in your project, you must confirm that the ADO260.chm file is present.
  2. Make sure that a registry entry exists for this .chm file in the following registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\HTML Help

    If a registry entry does not exist for the .chm file, add a new string value with the complete path to the file under this subkey. Use the same format as the existing entries for the new string value.
Note This resolution does not work for ADO 2.7. New versions of the Microsoft Developer Network (MSDN) from January 2002 are designed for Microsoft Visual Studio .NET and they cannot integrate with Microsoft Visual Studio 6.0 products.

MORE INFORMATION

After you fix this problem, context-sensitive help continues to open in a separate window; that is, when you invoke context-sensitive help for ADO objects, only the ADO help file (not the whole Microsoft Developer Network Library collection) is opened.

If you have the appropriate version of MDAC installed, but if you do not have the corresponding version of the ADO help file, you may have to download and install the same version of the MDAC Software Development Kit (SDK). To obtain the MDAC SDK, visit the following Microsoft Web site:

Microsoft Universal Data Access
http://msdn.microsoft.com/dataaccess

After you download the MDAC SDK, follow the steps that are listed in the "Resolution" section of this article.

REFERENCES

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

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

250334 PRB: MSDN Library Unable to Display Help from Within Visual Studio Programs

307189 INFO: New Versions of the MSDN Library Do Not Integrate with Visual Studio 6.0 Products

Modification Type:MajorLast Reviewed:2/25/2004
Keywords:kbprb KB251147
©2004 Microsoft Corporation. All rights reserved.