To scan slides, clean up the scanner bed of your flatbed scanner, and build a backlighter. Place the clean slide on the scanner with the backlighter over it, and use your scanning software to increase the resolution of the image. Scan the image, and use a photo editing tool to adjust its contrast and brightness.
Start by cleaning the scanner bed with a dry piece of cloth. Build a backlighter using a glossy piece of paper or a silver card stock. The backlighter resembles a triangular wedge with an open rectangular bottom. The shiny part of the paper or the card stock should be on the inside of the wedge.
Place the slide on the scanner bed, and put the backlighter on top of it. Using your scanning software, set the properties to the highest possible resolution. This ensures the scanner captures as much information as possible from the slide, especially since you may need to increase its size to create a regular size photo. You should also increase the brightness and set the dots per inch to the highest figure possible.
Scan the image, and save it on your computer. The image is probably darker than a regular photo. Use a photo editing application such as Photoshop to lighten the image. You can also cut out the white slide borders and increase the size of the image.