Customer Information - Desktop/Tower Labels with the serial number and support contact information are located on the front of the computer inside the ports door. Another label with only the serial number is located on the rear of the computer Inside the front ports door, on the right, a label provides the computer model number and serial number. Inside the front ports door, on the left, a label provides the following: Online Support Web address Tech Support phone number Tech Support hours of operation The label on the rear of the computer case is located below the fan vent. It provides the computer serial number and model number.