Most modern desktop and laptop comes with Windows 8 or 10 keys embedded in BIOS. With Windows being installed as VM, someone can find and retrieve Windows 10/11 key using Linux host OS. The key helps to activate the Windows version without any input from users.
$ sudo cat /sys/firmware/acpi/tables/MSDM | tail -1
If oyu are running Windows OS, you can also retrieve the product with wmic:
c:\> wmic path softwarelicensingservice get OA3xOriginalProductKey
OA3xOriginalProductKey
XXXXX-42F7Y-XXXXX-YRMYC-XXXXX