A Windows serial number is a unique 25-character code that identifies your copy of the Windows operating system. It is used to activate Windows and to verify that your copy is genuine. You may need to know how to check your Windows serial number if you are troubleshooting problems with your computer, transferring your Windows license to a new computer, or selling your computer.
There are several ways to check your Windows serial number. One way is to use the Command Prompt. To do this, open the Command Prompt by typing “cmd” into the Start menu search bar and then pressing Enter. At the command prompt, type the following command and then press Enter: