Thanks for joining the NUC community.
I am sorry to hear that have had issues with your NUC model DN2820FYKH.
Please bear in mind the board was designed for Microsoft operating systems that is why you get Windows options at BIOS level, since Linux support is limited on your computer.
Intel provides some recommended settings to install Ubuntu on your system however, I recommend contacting the Linux community for additional information about installing Ubuntu on your computer.
If this is a BIOS issue, you may try performing BIOS recovery:
Instructions for BIOS recovery available below: