Asus Motherboard P4S333-VM - Manual (Page 60)

4-4 Chapter 4: BIOS Setup
7. The utility starts to program the new BIOS information into the Flash
ROM. The boot block is updated automatically only when necessary.
This minimizes the possibility of boot problems in case of update
failures. When the programming is done, the message “Flashed
Successfully” appears.
8. Follow the onscreen instructions to continue.
If you encounter problems while updating the new BIOS, DO NOT turn
off the system because this may cause boot problems. Just repeat the
process, and if the problem persists, load the original BIOS file you
saved to the boot disk. If the Flash Memory Writer utility is not able to
successfully update a complete BIOS file, the system may not boot. If
this happens, call the ASUS service center for support.