IE Plug-Ins (QVP) in C# WebBrowser Control?

I'm writing a C# application that uses a System.Windows.Forms.WebBrowser control to access a web application.

In this web application we use a program (Quick View Plus) that integrates with Internet Explorer to provide in-browser viewing for a number of document types not normally handled by Internet Explorer (WPD, DOC, XLS, PDF, etc.).

My understanding of the WebBrowser control is that it shares settings with the user's own copy of IE, however, I am seeing different behavior between the two:

1. When I open the web application in Internet Explorer, all desired file types are successfully opened using Quick View Plus.

2. When I open the web application in the WebBrowser control, only PDFs are loaded in Quick View Plus (showing, at least, that it can run inside a WebBrowser control) - however, other formats (for instance WPD, XLS, DOC) are not opened in Quick View Plus - instead the browser 开发者_C百科downloads them and automatically opens them with the default application.

Why could this behavior vary, and what steps should I take to try to get it to behave consistently?

If relevant, IE8 is in use.