How Enterprise Mode works in Windows 10
The Internet Explorer 11 desktop application will be retired and go out of support on June 15, 2022 (for a list of what's in scope, see the FAQ). The same IE11 apps and sites you use today can open in Microsoft Edge with Internet Explorer mode. Learn more here.
This article describes how Internet Explorer Enterprise Mode works in Windows 10.
Applies to: Internet Explorer 11
Original KB number: 4019877
On a Windows 10-based computer, sites that are specified on the Enterprise Mode site list open automatically in Internet Explorer 11 and in Microsoft Edge.
This action occurs without any user input. For example, Contoso Travel requires Internet Explorer legacy proprietary technologies. The website was on the Enterprise Mode site list or in the Intranet Zone. When a user visits the following page in Microsoft Edge, the site is automatically opened in Internet Explorer 11.
On a Windows 10-based computer that has the Anniversary Update installed, when a site is opened in Edge and is redirected to Internet Explorer 11, the Open With Internet Explorer option is disabled and that message does not appear. Instead, the webpage is automatically redirected and loaded in Internet Explorer 11.
To re-enable the message, you can configure the following policy:
Show message when opening sites in Internet Explorer
In the Windows 10 Anniversary Update, the following new group policy makes sure that sites that aren't on the Enterprise Mode site list should default to Microsoft Edge:
Send all sites not included in the Enterprise Mode Site List to Microsoft Edge