When you press Help on the toolbar of a MMC snap-in, the Help file does NOT open, and no error message is displayed.

When you attempt to start the MSDN library, you may receive:

Cannot open C:\Program Files\Microsoft Visual Studio\MSDN98\98VSa\1040\msdnv6a.col.

These problems will occur if there is a problem with a tag in the hhcolreg.dat file, used by the HTML Help viewer (Hhctrl.ocx).

To fix this problem:

1. Open a CMD.exe prompt.

2. Type notepad "C:\Documents and Settings\All Users\Application Data\Microsoft\HTML Help\hhcolreg.dat" and press Enter.

2. Locate the XML tag.

3. Replace the XML tag with .

4. Save the file.

5. Exit Notepad.

6. Exit the CMD prompt.