The Canon Pixma MP620 printer can only communicate with computers that have the printer's drivers installed. The MP620 originally came with an installation disc that allowed you to install the drivers on your computer, but if you do not have the disc you can still install the drivers on your computer by downloading them from Canon's website. Downloading the drivers from Canon will ensure you install the version that is compatible with your computer's operating system, helping avoid problems with the printer's performance.
Turn on the Pixma MP620 and the computer you wish to use with the printer. Do not plug the USB cable into the devices at this time.
Open the computer's Internet browser and go to Canon's home page. Type "Pixma MP620" into the blank box next to "Search" and press the "Enter" button.
Click the "Drivers and Software" option under the MP620. Click on the operating system your computer has installed using the pull-down menu labeled "Select OS."
Click on the link under the "Drivers" section, then click the "I Agree – Begin Download" button to begin downloading the latest driver onto your computer. Click the "Run" button once the software has finished downloading.
Follow the instructions on the screen, which vary according to the operating system installed on your computer. When the software prompts, plug the USB cable into the back of the MP620 and the computer.