The Asus forums are full of people having problems with Asus Update, the moral to the story (which is too late for you now
) is to never flash Asus boards in Windows, the failure rate is far too high.
The board should be covered by warranty, you did nothing wrong. Its Asus and its dodgy windows flash software, users on the Asus member forums are crying out for Asus to post warnings or stop issuing BIOS updates using Asus Windows Update until the problems are fixed.
Scan should cover the warranty for the motherboard, according to Asus tech sites you deal with the retailer on motherboard warranties.
My board has died for other reasons (P5K Deluxe) which I didnt buy from Scan, the retailer of the board is dealing with my claim.
Mike