Windows has a built-in image viewer called Windows Photo Viewer that allows users to view JPEG files; to open a JPEG file in Windows Photo Viewer, double-click on it and the image is displayed. Alternatively, choose a third-party application as the default program for opening JPEG files.
To change the default JPEG program, navigate to the Control Panel of the PC, and select Default Programs. On the window that pops up, select Set Your Default Programs, and choose the desired program from the list. After you make a selection, a list pops up showing all the file types that the program opens. Select the JPEG file extension, and then click the Save button.