Windows 10: I lost my original windows product key. Can I buy another product key and use that to...

As in title. I can get a pretty cheap retail windows key on a keysite. But I would rather avoid the hassle of reinstalling windows and losing all my files just for a simple reactivation. I need a product key again because I changed motherboard and didn't bind my key to my microsoft account mistake on my part.On that keysite, they say it's for a fresh installation of windows. Is there no way I can just reactivate my current windows with a new key?

:)

 

Windows Product Key

A friend of mine has an all-in-one that came with Windows 8 pre-installed. He erased the original OS thinking he could install another version of Windows 8. One thing he encountered, that he didn't expect, the BIOS/UEFI has a password. So, basically he is locked out from installing another OS. His BIOS has the product key nestled inside. Is it possible to find out which version the product key belong to?

 

Activate windows 10 after re-installing (I have lost my product key)

I own a Lenovo T430 laptop. In 2017, I installed Windows 10 using my original Windows 7 product key. Unfortunately, I cannot find that product key anymore. I need to re-install windows 10. Will it be automatically activated after the installation, if I skip the step of asking the product key during the installation?

In my opinion, I believe that my laptop will have a digital entitlement stored on the Microsoft Activation Servers and this will not be a problem. Is that true?

If not, please suggest me a solution or a workaround.

 

Lost Original windows Product Key

I gave my laptop to my Cousin to use for some reason he uninstalled the Original windows 10 and Installed windows 7.. Now i lost all my drivers my Factory reset option and my original Product key. So is there a way to retrieve the same?