NHodz, Thank you for posting in the Intel® Communities Support.
In this case and based on the fact that you are using the Intel® Reference Design for Digital Signage E21 AIO, please sign in and submit your inquiry in our Intel® Resource and Design Center in order to get the most accurate assistance for this topic:
Also, you can always get in contact directly with the Intel® Authorized Distributors as well for further technical support on this matter:
Considering you also have questions related to the BIOS, then we recommend to contact the manufacturer of the computer directly since they customized everything in reference to the BIOS settings and versions on their products, including BIOS compatibility, they will be able to provide further details for this scenario.
Intel Customer Support Technician
Under Contract to Intel Corporation