I should just add, if you trust the source of your questionable copy, you can purchase a new Win 10 license, and manually put that key into your current build and have a fully legal and legit OS copy without requiring a re-install.
To do that...
Right click on your start menu and choose "System"
Down the bottom right, under Windows Activation, choose "Change Product Key".
However, you don't really know what else has been done to a cracked Win10 install. So a fresh start isn't a bad idea.