I hope you can help---Bios malware!

I've been fighting this for some time. I have a Gigabyte GA-Z77X-UD5H
motherboard in a desktop. I've had problems with the USB keyboard quitting
and malware scanners not functioning so I finally disconned the HDD and
made a new flash drive bootable, put Win 8 and a new bios update on it. After boot up,
when "Q Flash" is activated, everything works except "Update bios from
drive". The keyboard and mouse work until that line, then they quit, and
the bios won't update.
When I leave the bios and boot, a command line box appears:

Top of the box says: Administrator:X:\Windows\system 32\Cmd.exe
------------------------------------------------------------------
Microsoft Windows (ver. 6.2.9200

X:\ Windows\ System 32>



Anything I try to enter has ^ every other character.

If you have any idea how to remove this, I'll be eternally grateful.

 

Just to clarify, no operating system is installed, no HDD is connected.

 

Thanks anyway. This is the original, factory bios, I was trying to replace
it with another upgraded copy to see if I could dislodge whatever is
causing these problems.