Steps to  stop Microsoft Edge:

• Go to C:WindowsSystemApps and double-click it.
• Locate the 'Microsoft.MicrosoftEdge 8wekyb3d8bbwe' folder.
• Rename the folder by attaching '_DISABLED' to the end of the name, for example.
• The complete path of the Microsoft Edge folder should now be 'C: WindowsSystemAppsMicrosoft.Microsoft Edge 8wekyb3d8bbwe DISABLED' if you followed our naming example.
• In the short term, this should stop the browser, but a future Windows 10 upgrade may undo the name change to the Edge folder and re-enable the browser. To prevent this from happening, make sure the browser's update services aren't launched automatically.

Read More: How do I remove a Microsoft warning alert?