I finally found this web site

https://www.fmsinc.com/MicrosoftAcce...rols/mscomctl/

which helped me fix the mscomctl issue, but I had to go through all the steps and it wasn't until the very last one that I succeeded, i.e. deleting this registry entry:

HKEY_CLASSES_ROOT\TypeLib\{831FDD16-0C5C-11D2-A9FC-0000F8754DA1}

Still I'm at a loss as to what exactly triggered these catastrophic events. Was it a IE upgrade? The thing is it failed the same day on all my Windows 7 computers.