Many are looking for the serial number of Windows 10, 8.1, ... or even MS Server 2019, ...!
However, this is usually no longer available on the device or it is an OEM version. The serial number is actually called the product key and is required to activate Windows 10 this happens once during installation or if necessary if you want to enter / use a new product key. Even without hacking knowledge you can read out the serial number / product key on Windows!
All Windows versions have a worldwide unique key with which they can be activated. The so-called product key, formerly known as the CD key, is usually on the original packaging and you should keep it in a safe place. Because if Windows 10 needs to be reinstalled or, for example, the MS Office software, unless it is a shared MS Office 365 , you need the key.
PS: Please do not confuse with the ►► version number or the build!
|(Image-1) The Windows serial number on Windows All OS!|