Finally, turn on the option Always open PDF files externally.In the right-hand screen click on PDF documents in the middle of the Site permissions list.In the left-hand column, click on Cookies and sites permissions.In Microsoft Edge, press Alt+F (or click on the ellipses right below the X button in the top-right corner) and choose Settings.UPDATE: The latest versions of Microsoft Edge come with an option that lets you control how it handles the PDF files: If you experience such a problem, the following solution might help. You can try to change the default application once more, but soon Windows 'forgets' about your decision and starts opening them with Edge again.
However, in some situations, changing the default application for handling the PDF files does not stick: it may work once or twice, and then Microsoft Edge takes over, reverting the file association of the PDF files to itself. command that appears on the right-click menu for the PDF files. If you prefer another program to open the PDF files, you can set up that program using the Default Programs tool of Control Panel. Windows 10 comes with the new web browser, Edge, that is also set up as the default application for handling several other popular files, such as PDF.
