DiskCheckup is a hard-drive diagnostic application for Windows. Using the S.M.A.R.T. interface, the application displays a lot of information about your hard drive that you can use to determine its overall state. S.M.A.R.T. is a communication means between your hard drive and your computer's BIOS. Thus, when the feature is enabled in the BIOS, you can use this application to retrieve S.M.A.R.T. data.
The application itself won't let you know when your hard drive is dead or dying. By scanning your hard drive with DiskCheckup, you will gain access to lots of data. The more important information you should be looking at is the drive's total hours and the times the disc starts and stops over a period of time. Also of note is the spin up time. When those factors approach a threshold (you can see that after you carry out a scan), it might be time to replace the hard drive. DiskCheckup does a good job of organizing S.M.A.R.T. information for you. And, though the application does nothing for you but that, it is good to have all that important data in one place. DiskCheckup won't even start if S.M.A.R.T. is disabled in the BIOS or if your hard drive does not support the interface.