Flashing from within Windows? In AsusUpdate, go to the options and tick the "Downgrade Bios" box and click ok. Now update the bios from a file, search for the file and it should stop for a while, almost as though the app' crashed, just leave it and then it'll let you flash. Again, leave it alone to do its thing, after about 3-4mins it should be done. It may seem like it has crashed during the flashing process, but it hasn't!

DO NOT REBOOT IF YOU THINK IT'S CRASHED! FLASH IT AGAIN AND AGAIN UNTIL YOU GET A GOOD FLASH! Only once the flash has been verfied can you reboot safely!