|Yeah we should have thought about clearing the cmos earlier.|
Most motherboards have a 'clear cmos' jumper which does the same thing as removing the battery only it just takes a few seconds and not all day.
Locate the jumper on your motherboard. It usually consists of three pins. A jumper will be across two of them. That's the 'standby' position. With the power cord removed jumper it from the standby to the 'clear' position (the clear position will be the center pin and the pin not previously connected in standby). Leave it there for a few seconds and then jumper it back to the standby position. Then plug in the power cord and turn it on.
I've noticed on some asus boards the 'clear cmos' is just two pins. The jumper might be hanging from one of them or you may need to procure a jumper from another source. On some other asus boards 'clear cmos' was just two solder joints as if they forgot to solder the pins on. In that case you had to use a screwdriver across the two joints to make the short. Those were on older boards and I'd hope asus does things right now but you may need to consult the motherboard manual to make sure.