Do you have access to another computer / laptop? If so, try updating it on that.
I know it's not the most professional answer but if it works it'll save alot of time faffing about with various other options on your current machine.
Also, read the readme file about the firmware, it mentions something about it not working with Nvidia chipsets. From what I remember, if you have a Nvidia chipset, you have to update using another machine.