Many image formats used on websites have transparent backgrounds to allow what is behind them to show through. Creating transparent images with native Microsoft tools, however, can be difficult. Instead, use free software options to accomplish this task.
Image file formats that support transparency include GIF and PNG files. However, saving images into these file formats in Microsoft Paint will eliminate any transparency originally contained within the image. Paint allows for the user to paste an image with a transparent background by setting the Transparent Selection option under the Select drop-down on the Image section of the ribbon, but once saved, the image will lose all transparency properties.
Other Free Software Options
Paint.NET supports transparency in images. The user interface is modeled after Microsoft Paint, making it a bit easier to learn. The freely distributed GIMP software also supports image transparency, and it also provides other tools to enable experienced users to manipulate images at a more advanced level.