In the last few days, every time I boot my PC, my hard drive (WD 1TB Caviar Black) makes a loud whirring/grinding sound. This noise only lasts from the 'starting windows' screen until my computer has booted and the background programs have all loaded. I've used WD's LifeGuard Diagnostic tool to do both a quick and extended scan, which came back with no problems. I'm worried that every time I boot, I could be doing the hard drive damage! I'd like to know what this problem potentially is and how to go about it!