I have an HP ze5730us notebook PC. It was working fine until one day my wife updated some software and next time it came up it wouldn't boot up. It powers up and all the usual lights light up, but the only noise I hear is the fan. I don't hear any other activity from my notebook. I can't hear the HDD working and the fan will stay at full power as if it's stuck on the first step of powering up. Help I don't know what to do.