With a modded Bios on a RX 470/570, you need to use the pixel patcher to bypass the driver signature check any time you install or update the drivers. Download the pixel patcher, rename the executable to atikmdag-patcher-bios.exe, run it to patch the drivers and reboot.
You also need to set all the cards to compute mode in AMD settings to implement the ETH epoch Dag size fix or you will get a reduced hash rate due to the Dag size on ETH.