Does the WPF WebBrowser control always use Internet Explorer or does it use the default web browser on the system ?
Regards, MadSeb
Internet Explorer, though there are "hacks" posted on the internet which allow you to use a workaround in order to launch any browser you like.
This thread seems to explain one of the possible solutions.
One issue the Web Browser Control has that it’s perpetually stuck in IE 7 rendering mode by default. Even though IE 8 and now 9 have significantly upgraded the IE rendering engine to be more CSS and HTML compliant by default the Web Browser control will have none of it. IE 9 in particular – with its much improved CSS support and basic HTML 5 support is a big improvement and even though the IE control uses some of IE’s internal rendering technology it’s still stuck in the old IE 7 rendering by default.
This applies whether you’re using the Web Browser control in a WPF application, a WinForms app, a FoxPro or VB classic application using the ActiveX control. Behind the scenes all these UI platforms use the COM interfaces and so you’re stuck by those same rules.
See this: Web Browser Control – Specifying the IE Version
http://www.west-wind.com/weblog/posts/2011/May/21/Web-Browser-Control-Specifying-the-IE-Version
来源：https://stackoverflow.com/questions/3822537/wpf-webbrowser-control-what-browser-does-it-use