This is really strange, and I'm hoping I can resolve this without wiping out the user's profile on their machine.

Only ONE user on our domain is having issues connecting to our intranet website that is protected using Integrated Authentication.

The problem was occurring on IE7, and is still occurring on IE9 after the upgrade.  The IIS logs are showing no logon information for that user and the error code is 401.2.

The website is in the specified in the "Sites" for the Local Intranet zone, and "Automatic logon only for intranet zone" is selected.

I have tried other users on this machine (successfully), and this user on another machine (successfully).  I am to the point I'm thinking something is wrong with the profile.  I have tried to "Reset Internet Explorer Settings" from the Advanced tab, which to my understanding was supposed to clear the sites I specified for the local intranet zone - but didn't, and the procedure didn't work either.

Any suggestions?

I have just deleted the user profile and recreated it.

Specified the site as a local site in IE settings, and it STILL fails.

When the website brings up the password prompt, and I choose cancel (as it should be working automatically) I get the 401.2 error saying it is a configuration issue.  When I attempt to put in the user's password, I get a 401.1 error citing, invalid credentials.

I have tried other users on this computer and they were able to access the site with no problem.  I have also tried this user on another computer, again with no problem.

I am at a loss as to why this user is unable to view this website on this particular machine.

Thoughts, ideas?!

Have you tried using IE in no add-ons mode (iexplore.exe -extoff) ?
Even though other users of this machine can connect successfully, what is different about this machine? Particularly software that might latch onto the browser - toolbars, search utilities, pdf (or any other) viewer, web editing tools, etc.

I just tried it with -extoff, with no success.  There are no toolbars, search utilities, or web editing tools.  Adobe Acrobat is installed - but that would effect ALL users browser instances and not just this single user.

Just for game I installed Chrome, and it didn't even prompt for a password it just failed with ERR_ACCESS_DENIED.