A non-transitory computer readable medium has a universal driver executable on a computer. The universal driver includes instructions for: selecting a device for executing a function from connected devices according to an input from a user; sending a request to the operating system to set a communication port for communication with the selected device as a specified port; storing port identification information of a communication port for communication with the selected device and associated with the user in a memory; determining whether port identification information of the specified communication port matches the port identification information of the communication port associated with the user; sending a control command to the device to execute the function via the specified communication port according to a result of the determination indicating a match; and notifying the user of a different port being set as a specified port according to a result indicating a non-match.