Windows 10: Using Product Key for re-installation

I own a great lenovo T400 notebook. Trustworthy, with a battery still at 70% capacity. Solid. Whatever.My problem: Of course I have the genuine product key from lenovo for XP. During the years I upgraded to W7 and W10. Perfect. Recently the hard drive passed away. I put I new one. But now, I seem to be unable to reinstall W10 with that old key. I tried XP, in order to follow the previous upgrade path. Alas, to no avail. Maybe I'm wrong, but I don't see why a hard disk replacement should deprive me of using this system due to product key trouble. I used to have a functional one, upgraded, and s

:)

 

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.

 

Where is my Product Key if I want to re-install?


Like davidhk said. But if you really want to see your windows key, I would suggest Belarc advisor. It will give you some useful information about your system, product keys of your software is among them (not only Microsoft, you will have listed most of your keys).

 

Where is my Product Key if I want to re-install?

Cheers, will check it out.