You should be able to run the BIOS update from windows.
Can you get past the error for the battery when you try to update? Some laptops require an operational battery to prevent damage to the BIOS ROM. If you lose power while it is trying to update it may fry the chip, I've had it happen on some older computers.
some good info here
http://www.bay-wolf.com/bios.htm . There is a DOS command on that page that will force the update regardless of the battery. Just make sure you have a stable power source.