IF you´re using Vista x64 and wanna downgrade bios.
I did like this...

1. Flash the board with 0903 bios.
2. After the erase bios part, shut the computer down.
3. Restart computer and you´ll get a message for bios recovery.
4. Insert the CD that came with the box, or use USB-stick with the bios you want to be flashed. The bios must be named FORMULA.com
5. After successful bios recovery you are set to go