I am still getting this error.   It shows up in the Search Tab under both "MSDN Online" and "Questions".

I have applied the fix listed above, but our proxy uses port 8080.   I tried appending the port number to the fix like this:

<defaultProxy enabled="true" useDefaultCredentials="true">       <proxy bypassonlocal="True" proxyaddress="http://proxy.network.net:8080"/>    </defaultProxy>

But that didn't work either.   Any more suggestions?

Sorry for taking so long to get back to everyone on this.  If your proxy uses Windows authentication, the VS 2005 Help system fails to properly provide credentials to the proxy.  You can work around this using a config file change -- details below.  In this case, the Start Page will already be able to download its content correctly, as in Martin's case above.

There's another case that I didn't cover in my post above:  If your proxy uses another authentication scheme, such as LDAP-based authentication on a Unix box, then I'm afraid there's no guaranteed way to make VS 2005 Help work.  The client (VS 2005) needs to be designed to present a credentials dialog to the user when the proxy requests credentials, but this UI doesn't exist in VS 2005.

Some users have reported success with this workaround:

1. Start Visual Studio
2. On the View menu, click Other Windows -> Web Browser
3. A prompt for authentication should appear as the integrated web browser attempts to navigate to a page on the Internet. Provide a valid username and password.
4. The Start Page and online Help in VS may now function normally.

If you're in this situation, give this workaround a try and let us know whether it works.

Thanks!