booting problem

i have mercury mother board kob810efst, reasiently iformated system and re installed windows, total day it worked normally next day i am going to start it is not booting after power on hard disk, power led is glowing contuniesly cd rome is not working cpu fan is running display is not comming to monitor, i replaced the semons battery and reseted cemons, so please give a solution to solve my problem.