Dont remove usb cable before updating finished
I had problems with booting from USB on a Gigabyte H55M-UD2h.I tried everything i could find, even easy BCD and Drive Droid. Using Rufus (https://ie), under "Partition Scheme", I used MBR instead of GPT to create the bootable USB, I rebooted with USB above the Hard Disk in boot order, it worked!
Solution in my case: The 16 GB USB stick I was using was not considered as a removable device.When I boot-up those are the only options, despite having a USB stick plugged in then going into the BIOS and setting the UEFI USB stick as the primary boot device.The USB device is fine as I can see it in Windows/Linux and can read the files. This option can be found in most BIOSs called the Compatibility Support Module or CSM.You can learn how to reset the SMC on all Macs here in our detailed tutorial.For those with a Mac Book, Mac Book Pro, and Mac Book Air, all you need to do is this: The USB ports on the Mac Book should now work just fine, which you can confirm by connecting the USB device as usual and checking to be sure that it works – if it’s still not working, try another USB port, and try another USB device.