I have recently purchased a second HDD. It's WD Caviar Black 1TB. I use it as my system drive and my old WD RE2 500GB serves as backup drive now. Problem is that occasionally my PC locks up. For example music player stops playing, and then i can hear HDD spinning up, after few seconds all starts working again. Is that some kind of power saving feature? If it's a second HDD, then I can understand that, because nothing is using it and it could start spinning only when anti virus software is accessing files on it. *Power options are set to Maximum Performance *I don't know which HDD is doing that *All my drives and partitions are always listed in My Computer. *WD software shows that both drives are in perfect condition.