And BIOS is PY0031.BIO
You can choose the operating system in the BIOS. By default it is Windows 8. I got rid of the blue screen by changing that to Windows 7.
Windows 7 it is. And it is just that easy..
This document provides step-by-step instructions for how to install Microsoft Windows 7 from USB flash drive, on a NUC that only has a USB 3.0 port.