Download F6 from here -
http://www.gigabyte.com/products/product-page.aspx?pid=4959#bios
Extract/uncompress the folder.
Stick the file called F6 and 8MB in size onto a USB stick leave it plugged in.
Restart the PC.
Enter BIOS.
Select Qflash and enter this.
Choose update from drive.
You should see the USB drive name listed.
Select this.
Then you will see everything stored on this USB drive.
highlight the file called F6 and hit go.
It verify s it is the right one for you and away it goes.
It will restart etc.
As it has now wiped the BIOS, anything you changed before this update is lost.
So set it up again (boot order, XMP for the RAM etc).
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As for the 2TB HDD.
In disk management you see the dark grey shaded bar that is this missing HDD? right click and make a new volume/allocate the space and assign a drive letter.