Where can I see my product key?

I switched from my laptop to a PC. I had Microsoft Office on my laptop and then I always used Word. Now I don't know how to get my product key. Can someone help me?

The alternative is called https://www.magicaljellybean.com/keyfinder/, a program that, according to the manufacturer, also reads the keys from more than 300 applications.
Also http://www.nirsoft.net/utils/product_cd_key_viewer.html and the http://quadsoft.org/downloads would be good; both also named the serial number of https://www.pcwelt.de/...db_2204314 https://www.pcwelt.de/...db_2204314.