After installing the Internet Explorer 11 adm template, the Enterprise Mode settings are missing from the GPO. If you find Enterprise Mode settings missing from the IE 11 GPO, Microsoft say that this is because:
The other option if EnterPrise Mode is missing in the IE 11 GPO, is to use group policy preferences to enable Enterprise Mode via registry changes, using the following registry key:
Create a new empty String called Enable, in the following location:
In the same location, create another String called SiteList and enter a value of the URL to an xml list of sites to run in Enterprise Mode
❗ Tip: You can create the XML list using the Enterprise Mode Site List Manager tool.