Windows 10: lost product key after formatting

my friend gave me her asus vivobook windows 10pro and i need to format it after i format it the windows needs to be activated but i dont have the product key i tried to do the windows+x but different product key is showing what should i do?

:)

 

Lost of Product Key

I bought my Laptop in July 2015 with the Home and Student Microsoft Word. When I refreshed my computer I lost the Product key and I could not find the CD that contain the product key. What shall I do please suggest and help.

 

I lost my product key

We know nothing about your computer, or how you lost your product key.

More information is required to assist you correctly.

I suggest that you read this for suggestions on how to ask a question in help forums:

"Suggestions for asking a question on help forums"

http://support.microsoft.com/kb/555375/en-us

 

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.