I\'m trying to load the Chromecast background website into a c# WebBrowser but am getting:
Apparently when the WebBrowser control runs, it runs in in the version of IE installed on the computer, but it runs in IE7 compatibility mode. Trying to load the link you listed requires a more modern browser. As a matter of fact, the page you requested needs IE10 or higher.
You do need to change the browser emulation settings in the registry so that the WebBrowser control users a more modern IE feature set:
Internet Feature Controls
As you already said in your question, the two areas in the registry that need to be adjusted are:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
In each of those two locations, the process name of your applications is included with a DWORD value set indicating the level of compatibility. The specific values are found on the Internet Feature Controls help page. The names of the file is the name of you application "MyApplication1.exe", or if you're running from within Visual Studio, it is "MyApplication1.vshost.exe".
Because I have IE 11 installed, I set the browser emulation setting to 11001 and it worked for your linked webpage.