Black screen, capital accented N and a green block - Gigabyte GA-MA790X-UD3P

[Cyclocius]

 Directly in the computer, I tried both frontal ports and all the ones on the back.

[Dark Mantis]

That was quick as you had to shut down each time before rebooting. You did put the pendrive in the port before booting up didn't you?

[Cyclocius]

Yup, plug in, check it's secure, check the light on the stick is on, boot.

[Dark Mantis]

The point I was making is that in 2 minutes you had checked six ports and shut down each time in between and moved the usb sick and then rebooted and checked the Q-Flash utility for the drive! I just don't think it is physically possible.
Anyway I need my beauty sleep so I am off the bed now but if you would like to continue this tomorrow just log back on and I will be here.

[Cyclocius]

 Each restart was with a different USB socket, I'll try them all now, but thanks for your help, I'll be back tomorrow 

[Dark Mantis]

OK see you then
 

[Dark Mantis]

This morning I thought I would take the opportunity to check the BIOS update file's integrity and so I have downloaded it and extracted it and all the files are there as expected. I even checked with the F6 BIOS update as the F7a is still a Beta version but there was no problem there either. From that I deduced that the problem must be to do with your computer. For some reason it is not actually recognising the USB pendrive. So I think we will have to go back to basics here especially as it is your first computer build.
We will clear the CMOS and load BIOS optimised defaults if possible.

[Cyclocius]

 Okey dokes, that's all done from the BIOS menu right? Shall I go and do it now?

[Dark Mantis]

Sorry my bad.I misread your post! Go to the FAQ section here: http://forum.giga-byte.co.uk/index.php/topic,2286.0.html and follow the instructions.  Do as I suggested  and let's hope today is a little more profitable

[Cyclocius]

 Righty ho, loaded optimised defaults and cleared the CMOS. Shall I plug the USB stick in in?

[Dark Mantis]

No, please read my last post it will explain.

[Cyclocius]

 Oh dear. Steps 2 and 3 look hard, 2 secs.

[Cyclocius]

Okay, I went with step 2, held the screw driver in place for 5 seconds, plugged back in, power on, loaded optimised defaults, saved and exited. Now what?

[Dark Mantis]

Well done. Next are you sure that you plugged in the front USB ports to the motherboard? If you are you can insert the USB pendrive with the update file on it and try to do the same as yesterday eg press"end" as it's booting.

[Cyclocius]

Gotcha, will report back.