JPG is a file format that compresses an image and makes it as small as possible for online distribution. Because the JPG format results in high-quality images with small file sizes, you commonly see this format as you browse the Web. Download a JPG image to your computer and use one of three options in Windows 7 to open the file.
Right-click a JPG file in Internet Explorer, then click "Save Picture As" to save a copy of the file on your computer.
Right-click the file on your computer, then click "Preview" to open it in the Windows Photo Viewer application.
Click on the file, then click "Open" in the file menu to open the file in your computer's default image viewing application. If you have not installed an image viewing application, the file will open in Windows Photo Viewer, which is native to Windows.
Select "Edit" from the file menu to open the file in your computer's default image editing application. The native image editor in Windows is Microsoft Paint.