INTRODUCTION IN OCCASIONAL PROGRESS: There always seem to be more interesting things to do than write introductions.

The Shell Document Viewer (SHDOCVW)

In a very real sense, SHDOCVW.DLL is Internet Explorer. Though some users start Internet Explorer by running the program IEXPLORE.EXE, and some even consider that this program is the essence of the product, IEXPLORE has long been little more than a front end for executing SHDOCVW. Other users start Internet Explorer by double-clicking an icon on the desktop. Like those for My Computer and the Recycle Bin, the icon for Internet Explorer is distinctive for not having a shortcut overlay. Instead of being a shortcut to run a program, it is a shell namespace extension represented in the registry by a CLSID. Double-clicking tells the Windows shell to resolve the corresponding CLSID, which loads SHDOCVW. Pretty much any way to start Internet Explorer is just a way to get SHDOCVW loaded.

Well, that is how things stood until Windows Vista…