removing the battery probably cleared the cmos memory but just in case, have you tried to clear it manually too? (the manual of your motherboard should have instructions on this). See if that helps. Also, try and remove all equipment that is not essential to start the boot process (e.g. hard disks, peripherals) and leave only cpu, video card and memory. You can also remove the memory and see if the motherboard complains by beeping several times. Was there a particular reason you removed the battery in the first place?