Which BSOD error are you getting?
Do any of the other F commands work, such as F10?
Also, have you updated to the latest BIOS for your NUC?
Thanks for the fast answer. From beginning I had only problems with my NUC and now this.
What is BSOD? If you mean errors from blue screen then no. There are no errors, only blue colour.
I have NUC 34010WYK and my bios v I think is 32.
But why sometimes I can start my window and sometimes not. The time I can start the windows is when i can see F2 to enter bios settings.
You should consider updating the BIOS on your NUC to latest version: https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=24536
Press F2 Immediately up and down several times as soon as you turn the NUC on. Once you are in the BIOS try setting the default settings by pressing the F9. Make sure Fast boot is disabled.