Reinstalling windows 10

[akshwork1]

Hello everybody! I had windows 10 installed originally on my laptop, it crashed and I decided to install windows 7 also used disk part command before installing windows 7. is there a way to re-install windows 10 and get the licence key back so the operating system becomes genuine?

 

[clutchc]

If the W10 you had installed was legal and if it wasn't an upgrade from the W7 you reinstalled, it should activate automatically.