Hi, you said you tried to remove the battery, did you remove it? If not, completely remove the cmos battery and unplug the power cord from your power supply and wait at least 10 minutes. Then replace the cmos battery and plug the power cord back into the power supply. This should reset all your bios settings back to default and allow the system to post. If the system still doesn't post, try replacing your memory modules with new / different ones if you have access to any.