General Failure. The parameter is incorrect.

Today, out of the blue, a user informed me that he could no longer follow hyperlinks from within Outlook 2007. The error he would receive simply stated "General failure. The URL was: "http://www.test.com/" The parameter is incorrect". I found a lot of references to this being an issue with the default web browser and I attempted to reset this default in every way under the sun. I changed it in the Internet Options control panel. I used the program defaults tab of Add/remove Programs control panel. I installed various other browsers in an attempt to cause one of them to fix the broken setting. I changed the file type handlers from the Folder Options control panel. I even tried manually editing the registry entry for http and https protocols. None of this had any affect whatsoever on the error in Outlook. I performed a repair install on Office, I updated to the latest service pack, all in vain. The only solution I've uncovered was to uninstall ie8. Issuing this command: %windir%\ie8\spuninst\spuninst.exe will revert to ie7 which of course cannot be safely used at this point in time. At least after uninstalling ie8 firefox or chrome is able to install itself as the default browser successfully.