Did factory restored deleted my product license key

[birgs]

I restored my laptop to factory default without any backup because i want to uninstall useless programs, then my windows 8.1 updates uninstalled. I worried so much if my laptop now is pirated because after reset to factory default i can't now install any programs it kept saying the files signature is invalid or corrupted, and i can't find product license key. Any idea about these big problems. my laptop is Gateway N522. thanks for help.

 

[jmshub]

Windows 8 doesn't use the traditional product key. The secured boot bios handles registration.