Recently we’ve covered Microsoft Edge Stable when installed on Windows 10 will hide Classic Edge and it is not possible to uninstall. Another thing we noticed recently is it also takes over from Legacy Edge or other PDF applications, and set its self as “Default PDF Reader” in Windows 10 version 1903.

We all know Microsoft Edge not only comes as the default browser on Windows 10, but it also is the default PDF Reader, we’ve covered how to change that and make another PDF app as default. Things have now come full circle now.
Microsoft has started publishing updates to Windows 10 to make Chromium Edge more prominent and its predecessor Microsoft Edge less discoverable.
If you now install Microsoft Edge Stable (although not officially available) it will be set as the default application to handle PDF files on Windows 10, here is how you can change that.
1. Click on Start, open Settings app > Apps > Default Apps
2. Click “Choose default apps by file type”
3. Scroll down until you find “.pdf”, click on Microsoft Edge

4. From the desktop Applications displayed in the pop-up dialog, such as Sumatra PDF or Adobe Acrobat or Foxit Reader or any other, select one, done.
You should expect Microsoft to ship Edge Chromium as the default browser in future versions of Windows 10 and it also will be the default PDF Viewer. What do you say about these changes?