Yes download that. Do you know somebody who has already flashed a BIOS and knows what to do if something goes wrong? Would be a good help, since otherwise you'll have to read a bunch about that first. Basically, you download a self-extracting *.exe file and put its contents on a bootable floppy or CD in order to run the flash program from a clean DOS. The Gigabyte file contains an Autoexec.bat that starts the flash program automatically with the BIOS image after booting from the floppy or CD.
In the manual for the GA-8I848P/775 I found this interesting passage: "Some advanced options are hidden in the new BIOS version. Press Ctrl and F1 together after entering the BIOS menu and you will able to see these options". Maybe your BIOS has a similar feature?