this motherbord dont have flashback butoon!
You need to be IN your bios to flash it from the USB stick. This info is from your manual. Hope this helps you.
Chapter 3: BIOS Setup
ASUS EZ Flash 3
To update the BIOS via Storage Device(s): <----------
1. Enter the Advanced Mode of the BIOS setup program. Go to the Tool menu to select
ASUS EZ Flash Utility and press .
2. Insert the USB flash disk that contains the latest BIOS file to the USB port.
3. Select via Storage Device(s).
4. Press to switch to the Drive field.
5. Press the Up/Down arrow keys to find the USB flash disk that contains the latest BIOS,
and then press .
6. Press to switch to the Folder Info field.
7.Press the Up/Down arrow keys to find the BIOS file, and then press to perform
the BIOS update process. Reboot the system when the update process is done.