Once you have downloaded the file, you cannot simply double-click it to run it. Since it is a set of instructions, you must "send" it to the printer port. Open CMD as an administrator.
If you aren't sure of the model, check your Device Manager. Look for the hardware ID in the properties of the "Unknown Device." Dccv1-51-prn File Download
Often found in manufacturing environments for barcode and label creation. Once you have downloaded the file, you cannot