The Settings will now launch. Go to Settings by typing it in the Search bar or looking for it in the Start menu.    

How do I widen the display to fill the full screen? – Microsoft Community.Tutorial: 3 Ways to Fix Stretched Screen Display Problem on Windows 10

  Open your Display settings Scroll to Scale and layout. Typically, it’s best to choose the one that’s marked Recommended. Step 3. The stretched screen issue can be caused by faulty display settings. All edges of the taskbar, for example, should be completely yow. Find Display resolutionand then choose an option.  

– How to stretch your pc screen

  Step 8. Can you help us improve? Navigate to the Monitor Properties section and look for the screen position and size settings to make changes.