Defraggler is able to analyze your drive and provide results on the current health of the drive.
This is done by analyzing the S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) data to gauge its reliability and performance.
The Health tab displays S.M.A.R.T data about drive that is currently selected on the drive list.
The most important point on this display is the “Health” indicator - if it’s “GOOD”, then you shouldn’t have any worries about the drive’s status. However, if it shows “WARNING” or “ERROR”, then this is a good indication that any important data should be backed up and the drive replaced, as that indicates an important S.M.A.R.T. parameter is showing a concerning result.
You can find out more information on S.M.A.R.T data here!
Some of the critical parameters would be 5: Reallocated Sectors Count, 187: Reported Uncorrectable Errors, and 198: Uncorrectable Sector Count, all of which should be 0.