Thank you, Brink.
It should be okey for me to enable it now or it should be done before installing a new OS? I did a clean install of Windows 10 but i don't know if we can still enable it without breaking anything.
I changed my system from Legacy/MBR to UEFI/GPT. Do i need to enable Secure Boot? Everything runs normally, i don't really understand what Secure Boot is or if it needs to be enabled for some reason.