The key is recorded in the system BIOS, and is automatically read if needed during a re-install.  You can see the key using one of the free system scanning utilities such as Belarc Advisor.
I bought a Dell Inspiron 14-5447 laptop that has WINDOWS 8.1 pre-installed. I made a recovery disk, but I couldn't find license key anywhere. Don't I need to have a license key if I ever need to re-install the OS? How could I find the license key? thanks,
how to find the license key for WINDOWS 8.1 that was pre-installed?