Reinstalling Windows on a new hard drive for a laptop

[natey7]

The hard drive on my laptop died and I am going to replace it with a fresh one. When I reinstall Windows on this new hard drive, am I going to need a product key? If so, how would I retrieve the key?

 

[Colif]

No... If windows 10 was activated before it will reactivate again on the hardware

When you install win 10, and get to screen asking for a Licence, click "I don't have a key" and win 10 will continue to install and then once complete, check its activation servers to confirm PC is registered to use Win 10. All info of PC + product key + possibly an email address are recorded on a Microsoft server so you don't need to know it anymore.