On Windows 8.1 or later, once PolicyPak Browser Router is licensed, it becomes the “default browser” in the operating system, like what is seen here.

However, if you are using the Legacy Browser Router mode and unlicense PolicyPak Browser Router or remove the computer from the scope of any PolicyPak Browser Router rules, you will find that PolicyPak Browser Router Agent is apparently maintained as the OS’s default browser.

This is a “Display Only” and “Cosmetic” issue and not reflective upon reality, this is by design. Usually, IE will now actually be the default browser as far as the user EXPERIENCES it.

That being said, once you have unlicensed PolicyPak Browser Router it is not active any longer.
Therefore, (when PolicyPak Browser Router is not present.) … an end-user could open up Firefox, Chrome, IE or Edge … like what is seen here…
 

And manually set the default browser, or use the operating system itself to specify the desired default browser .. like what is seen here…
 

Afterward, they should see the OS default web browser change accordingly and be maintained correctly at the next login.

Note: When not using Legacy Browser Router mode and you remove the computer from the scope of any PolicyPak Browser Router rules or unlicense PolicyPak Browser Router after having a PolicyPak Browser Router policy in place the default behavior is to revert the default browser to the value present before PolicyPak Browser Router was enabled/licensed.
 

What if:

• You really, really don’t like PolicyPak Browser Router displaying as the default browser, even though the problem is only “cosmetic.”
• You want to FORCE SET a default browser and ensure it for the user (but this time, not using PolicyPak Browser Router).
• You want to set a specific browser as the default, THEN let the user change it after you set the default, say, to IE.

For either or all of these options…

Step 1. ONLY if using the following PolicyPak Client-Side Extensions ADMX setting set to Enabled, (aka Legacy Browser Router mode), OR if Client-Side Extensions version 2535 or older was ever installed on the machine.

You have to delete this file first…as a one time action using GPPPrefs 
 if 

Step 2. Then if you want to FORCE A PARTICULAR BROWSER VIA POLICY … (pick ONE)

• Use PolicyPak File Associations Manager to set HTTP and HTTPS to Internet Explorer. This is supported as long as you are NOT using PolicyPak Browser Router any longer. Link for more details.
• Use the in-box Group Policy method for File / Protocol Associations (not recommended, since you have PolicyPak File Associations Manager, and this method is not dynamic NOR can you use it ALONGSIDE PolicyPak File Associations Manager, so it is NOT recommended): Link for more details.

Remember: The two methods above PERMANENTLY AFFIX it to IE, and don’t make it changeable. (Technically, the user CAN change it, but then it’s ‘snapped back’ every time the user logs off and on.)

-ANOTHER OPTION- … INSTEAD of forcing a particular browser, you can SET ONE BROWSER as the DEFAULT, then let the user CHANGE

“How can I set it to IE, then make it changeable by the end-user?”
To do this.. we found a utility, which you can likely DEPLOY ONCE via PolicyPak SCRIPTS on the USER side .. (we didn’t test that, and only tested it manually on the user side)…

http://kolbi.cz/blog/2017/11/10/setdefaultbrowser-set-the-default-browser-per-user-on-windows-10-and-server-2016-build-1607/
(PolicyPak makes no warranties about this tool.)

When it runs.. it works instantly.. and sets the default browser. In this example, we set it to IE.
And then it was later changeable by the user.

Note: If you uninstall the PolicyPak Client Side Extensions on a machine where PolicyPak Browser Router was set as the default browser then Microsoft Edge will become the default browser immediately after the PolicyPak Client Side Extensions are uninstalled. You will see the notification below on your screen and if you check the default apps you will see that Edge has become the default browser.