Oh, and I got Winamp 5 to start working again!!! 

I figured it out:  somehow, during my "normal use" of Winamp 5, files or registry keys were corrupted.  I uninstalled Winamp 5, then installed Winamp 2.95 in the same folder.  When I opened Winamp 2, it gave an end task message without showing anything.  I uninstalled Winamp 2, which deleted the entire folder.  Then I installed Winamp 5.09, and everything works like a charm again. 

So try the same method with Firefox..