Flashing Gigabyte while avoiding "Invalid BIOS image"

Thanks @suikoden - I think maybe this is due to CMD prompt not ran as admin, sorry for not mentioning. Please run as Admin, select version folder, hold shift and press right click, choose open command window here.
If that does not make admin CMD prompt for you, you may need to right click from start menu and hold shift, then choose run as admin, then navigate via CD to the folder on your desktop with the files