To put it simply, OEM licenses are pre-activated licenses, supplied with new computers on which Windows is already installed and ready to use. This license is, in fact, attached to the machine on which it is located and can only be used with it. OEM licenses are usually registered directly in the BIOS or UEFI firmware of the PC. That’s why you don’t need to reactivate your copy of Windows when you reinstall Windows from a recovery partition on the PC.
The Windows Retail licenses are commercial licenses, which you bought in a paperless version or in a boxed version online or from an official reseller. In the dematerialized (or digital) version, the license is associated with your computer and attached to your Microsoft account. Concretely, you just have to connect your new computer to the Internet and identify yourself with your Microsoft account so that the activation of Windows is done automatically. If you have purchased a boxed version, you should have a physical installation version of Windows (such as a DVD, or a USB key in the case of Windows 11). The license is usually written somewhere in the box. Retail licenses can be transferred from one machine to another, but can only be used on one PC at a time.
Windows Volume licenses are, as the name implies, licenses sold in batches to companies, associations, governments, in education, etc. and can be installed on a limited number of computers. Once this limit of the number of computers allowed to activate Windows is reached, this license key can no longer be installed on another machine. This is typically the kind of license you can find in attractive offers where the Windows 11 activation key is charged less than ten euros. These license keys can potentially be reused, provided of course that their maximum number of uses has not been exceeded.
How to know if your license key is reusable?
To determine if the Windows license key used on your old machine can be reused on your new PC, a simple command line is enough.
- Open the Command Prompt
From a Windows Administrator session, use the keyboard shortcut Windows + R, then in the Run window that appears, type cmd and press the Enter key to confirm. - Determine the type of your license key
To find out the type of license key used to activate the copy of Windows on your PC, copy and paste the command Slmgr -dli into the Command Prompt and press the Enter key on the keyboard to confirm.