I recently ran into one of the most perplexing computer problems I've experienced in a long time. Naturally, the resolution turned out to be head-smackingly simple.

It involved Internet Explorer 7 on Cynthia's computer (Windows XP). It began opening two or more windows when you clicked on a Favorite or typed an URL in the address bar. The new window(s) froze and I had to go to Task Manager, find the IEXPLORE.EXE process and End Process Tree to get rid of them. If you clicked a web link in Outlook Express, some 60+ blank IE windows popped open all at once. Oddly, if you ran IE from the quick launch icon and clicked a link on the initial home page, it worked normally.

After hours of Googling and experimenting with fruitless scans and solutions, it turned out all I had to do was re-install Internet Explorer 7.

If I had taken the time to think about the symptoms in context, it would have been obvious what to do. Earlier in the week I had re-installed Windows XP because the computer mysteriously stopped booting. (I am still not sure what happened, but when I shut down the computer to install a memory upgrade, it froze during the shut down, so I just turned it off. After that it wouldn't boot again until I re-installed Windows XP.)

Re-installing Windows XP (with Internet Explorer 6) over the existing installation of Internet Explorer 7 undoubtedly threw something out of whack. It also messed up Windows Update: While diagnosing the IE problem, I found that there were some 80+ Windows Update patches waiting to be installed, but they all failed to install until I downloaded and forcibly re-installed the Windows Update Agent.