A JPEG image is a digital picture file format. It is one of the most commonly used formats for posting images electronically on the web or via email. A JPEG image can be resized using one of many digital image-editing software programs. Microsoft Paint often comes pre-installed on many PCs, especially if they have the Microsoft Office Suite.
Open Microsoft Paint and click on "File" on the menu bar at top, then select "Open" and choose the JPEG image you want to resize.
Select "Image" from the menu bar at top, then "Stretch and Skew." A pop-up dialog box will appear and give you some options for resizing your image.
Type a percentage in the editable boxes labeled "Horizontal" and "Vertical." If you type the same percentage in each box, your JPEG image will be scaled up or down proportionately.
Click "OK" and your image will be resized. Note that enlarging the image may cause it to have an apparent reduction in resolution or clarity, while reducing the image will have the appearance of a sharper image in relation to its size.