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.
Are Windows 10 OEM keys reusable?
Once an OEM licence is registered against the device (motherboard) it can be reinstalled to the same hardware as many times as you like.
How many times can you use Windows OEM key?
On preinstalled OEM installations, you can only install on one PC, but you there is no preset limit to the number of times that OEM software can be used.
Do OEM Windows 10 keys expire?
No OEM keys do not expire for the lifetime of the device.
Is OEM key lifetime?
NO ANNUAL FEE – NO TIME LIMITATIONS – LICENSE VALID FOR THE LIFETIME.