There are a few reasons why this may happen. First, make sure your printer is connected to the computer either by USB cable, WiFi, or network cable. If you are unsure if it’s connected properly, check the printer manual for instructions. If you are using a WiFi / network printer, make sure your computer is connected to the same WiFi network name (SSID) as the printer. Once it’s connected, reinstall the software / printer driver included with your printer. If you do not have the original disk, refer to the manufacturer’s website.