Initially I tried a repair of Office. Still stalled. I removed and reinstalled Office. Excel worked with DDE. I did an Office update to install Service Pack 2 and a couple of updates. Excel stalled. I removed one of the updates, *** Update for Outlook Junk Email Filter 2003 (KB923095) *** and rebooted. Excel worked with DDE. I did another Office update to get additional updates required after the installation of Service Pack 2. I downloaded the Junk Email Filter again and installed it also. Excel stalled. I removed the Junk Email Filter and rebooted. Excel worked with DDE.

When I decided to reinstall Office I thought the best that I would get was Excel working again but that I would not know what initially caused it to fail. As it turns out I found a very specific cause, *** Update for Outlook Junk Email Filter 2003 (KB923095) ***. What this has to do with DDE I have no idea. I am just glad that I found a specific cause for the failure and that it was so simple to remedy.