After opening the Command Prompt window, execute the below command.Right-click on Command Prompt and select the “ Run as administrator” option.Type “ Command Prompt” in the Start menu search bar.Open the Start menu by pressing the “Windows Key” on your keyboard.With a single line command, you can find Windows 10 license key in the Command Prompt. How to find Windows Serial Number from Command Prompt This is because your Windows 10 machine is linked to your Microsoft account. To be precise, you will have a generic Windows 10 serial number. Important Note: If you’ve upgraded from Windows 7 or 8 to Windows 10 for free or if Windows 10 is activated using the digital license, you will not have any license key. How to Export Serial Number to Text File.How to find Windows License Key from PowerShell.How to find Windows Serial Number from Command Prompt.When needed, use one of the below methods to quickly find the serial number of a Windows computer. The good thing is, there is always a way.