Open up a command prompt with administrator privilages, either right click and Run as Administrator, or hit the Windows Key type in cmd and then hit CTRL+Shift+Enter.
Sometime you may need to turn it on so you can install a modded driver or something, other times it needs to be turned off so you can install EasyAntiCheat…
bcdedit -set TESTSIGNING ON bcdedit -set NOINTEGRITYCHECKS ON
bcdedit -set TESTSIGNING OFF bcdedit -set NOINTEGRITYCHECKS OFF
Reboot for the changes to take effect