You can reuse your windows activation key as many times as you wish. The activation key cannot be activated on two different computers at the same time.
How many times Windows 10 key can be used?
You can only use a Windows 10 key once on a PC or laptop. If you need to reinstall the operating system for any reason, you’ll need to enter the key again.
Can I use same Windows 10 product key twice?
you can both use the same product key or clone your disk.
Can you use your Windows 10 license key code more than once?
No, the key which can be used with either 32 or 64 bit Windows 10 is only intended for use with 1 of the disk.