Many digital images are stored on computers in the JPEG file format to save space. You can use Paint, a basic image editing application included with Windows, to blow up a JPEG image to a larger size. Even though Paint can increase the size of an image, it cannot increase the detail, so images blown up too much can appear pixelated.
Open your computer's Start menu, type "Paint" and then click "Paint" under the "Programs" heading.
Click the blue button to the left of the "Home" tab, and then click "Open." Highlight the JPEG image file you want to blow up, and then click "Open" again.
Click the "Home" tab, and then click the "Resize" button. The "Resize" button is in the "Image" section of the Ribbon.
Type the percent you want to resize your image by in the first "Horizontal" field in the dialog box. If you do not want to keep the same ratio of height to width when you blow up your image, uncheck the "Maintain aspect ratio" box and type the percent you want to resize your image vertically in the first "Vertical" field.
Click "OK" to blow up your image.
To make an image larger, you will need to enter a percent greater than 100. Instead of resizing an image's dimensions as a percent of the current dimensions, you can set precise dimensions in pixels by clicking the "Pixels" radio button in the "Resize and Skew" dialog box.