That’s why you are asked to enter a product key while installing some specific software and Microsoft Office is one of them. A product key is formed when those serial numbers are combined. Because of this reason, different serial numbers are assigned to each program and any person can buy those serial numbers to legally use that application. Among those different methods, most of the commercial software is protected with a serial number in order to eliminate theft and unauthorized installation. There are different security measures used for each software to deter illegal copying of it.
