[DaiPlusPlus]

What happens if you run an EdgeHTML-using application on Windows 7 or 8? I noticed that the EdgeHTML control in WinForms and WPF is not a drop-in replacement for the old WebBrowser control (i.e. it isn’t a subclass, so you must use one or the other, but Microsoft didn’t document the best way to switch between controls based on feature-detection).

[chrismorgan]

When you try to call the API, it will fail as it’s not there. The precise failure mode will depend on the application. One possibility would be to crash outright. Another would be to try the EdgeHTML control, then fall back to MSHTML. Yet another would be to try EdgeHTML, then complain in an alert, notifying the user of the requirement for the new version of Windows.