I've just downloaded the Bios zip file for your motherboard to have a look. The included document "How to flash the BIOS.doc" is indeed confusing as it starts by saying DON'T FLASH FROM A FLOPPY DISK!!!! and then goes on to tell you how to make a boot floppy. What's that all about?
From looking at the document and seeing that you have a SATA drive I think that the safest method for you will be the last one "Flashing the BIOS for Non-FAT file system" where you boot from a Windows 98 boot disk and copy the flash utility "ADSFI713.exe" and the bios file "A7043VMS.200" to the RAM drive created by the boot disk. If you don't have a Win98 Boot disk you can download a suitable one from click here choose the Windows 98 SE OEM version as this one creates the necessary RAM disk.