Your post appears to have an error in the name of the DLL. But no, Microsoft didn't do as you wrote but they don't backup your files either.

We only lose what we don't backup.

If you run the Control Panel, Add/Remove programs and select IE/OE then take its REPAIR option.

-> http://support.microsoft.com/default.aspx?scid=q270670 tells how to backup and restore. If you don't, that's your choice.

Bob