Windows 10: At display's right and left sides are black borders and usable screen has got smaller

My computer's display just shrunk! At right and left sides are black borders and screen has got smaller! How can i fix this?

:)

 

Black borders on screen

Hi Lyn,

It is true that the challenges that you’re having with the black borders on your computer screen might be related to the Display Settings of your monitor just like what DaveM121 was suggesting. To better assist you with your concern, we need you to answer
the following questions:

• Which type of display cable are you using? ( VGA, DVI, HDMI cable).
• Were you able to update your display adapter drivers?

Looking forward to your response.

 

Black Screen on Left Side of screenshot

When I take a screenshot of my Surface Pro 4, the left side of the screenshot is totally black, and the right side only shows the left half of my window.

Is that a problem of the display setting? It also affects the screen-sharing in a web meeting.

 

Black border around monitor

I tried the steps you suggested and it did not change anything regarding the black border. I am trying to come up with a better explanation, the information on my screen has a black frame around the information on my screen. The display does not go from
corner to corner of my display monitor. There is a 1 inch thick black bar on the left and right sides and a 1/2 inch thick black bar on the top and bottom. I attached the screen shot per your request but it is only showing the information on the screen up
to the black frame. I can get rid of the black frame by going to a lower resolution but I didn't think that is the right solution. I should be able to upgrade to windows 10 and still have the recommended resolution for my monitor.