Hey there,
just for the record, using an ASUS board featuring EZ-Flash you don't need any DOS type stuff on the flash/thumb drive, you just download the BIOS from the web, save it to the flash drive, reboot the PC and enter BIOS and then load up EZ-Flash from within the BIOS options and point it to the updated BIOS file on the flash drive when asked.
Couldn't be easier (assuming u have a flash drive!).