GSmartControl lets you monitor your hard drive's health in detail

S.M.A.R.T is an acronym that stands for Self-Monitoring, Analysis, and Reporting Technology. It's a nice bit of intelligence that hard drive makers have been including into drive firmware for several years now. In simple terms, it's supposed to let you know that a drive is about to crash before the crash happens. You can then take measures to protect your data or, perhaps, return the drive to the