can't Access Bios on gigabyte mb

Are you using cable USB keyboard?

Possible causes of this are:
- you are just pressing power button on PC. In windows select restart - this is real restart cycle in Windows 10. Normal power on /off is sometimes so quick you are not seeing BIOS options all.
- user is putting PC to sleep instead power off
- using wireless keyboard
- pressing Backspace instead of "Delete" key

Try these and report back

edit: if non of the above works, try to clear CMOS (take out battery, or short circuit jumper - read manual)

You might have Fast Boot enabled on your system which makes things go by too quickly for the special function keys to kick in during initial book. You can tell Windows to boot into BIOS/UEFI by using "Advanced Startup Options" in the OS. Start, Settings, Update & Security, Recovery, Advanced startup. Or just try the searchbox/Cortana with "Advanced Startup." This puts you into the Choose an option screen upon bootup, where you can "Use a device" to boot from a USB drive, network connection or DVD, or use the Troubleshoot option to attempt various forms of system update or repair (restore, image recovery, startup repair, command prompt, and startup settings changes).
For access to UEFI, Brink has a tutorial on that subject that also works from inside the OS. I don't think you need the legacy BIOS info, given your mobo...
HTH,
--Ed--