Microsoft Photos app which is the default photo viewer and editing tool in Windows 10 makes it easy to remove or change background of images.
Here is how to do that:
Open the image to be edited in Photos and click the Edit button from the top left corner.
Click the Background icon. This will display three choices in the right pane: Blur, Remove and Replace.
Use the Blur option to blur the background. The Remove option will delete the background from the image and replace it with a white background.
You can add custom colors as the background with the Replace option. With the Replace option, choose the required color from the palette.
Once the changes are made, click the Save options drop-down. You can then either overwrite the original image, copy the image to clipboard or save the edited image as a copy.
All done.