Hello,
i have just read eveyones problem wit the 500 gig hdd, im guessing they all seagate drives???
check the model number ie: 7200.10 or 7200.11 if you have one of these to you should throw it away....
western digital 500gig drives have never given any problems, it could also be that your bios needs an upgrade.
Configuration: Windows 7 Internet Explorer 8.0