I remember purchasing my second customized computer through a local computer store. Although I was anxious to get the new system into my hands, the store technical support person said I'd have to wait until my system was completely “tested by SpinRite.” Gazing at my new monitor, I saw at a box moving slowly across the screen -- and had no idea what was happening.

The tech support person told me that SpinRite was checking the hard drive very carefully for defects and marking those sectors off so that the operating system would not use them. This was circa 1992.

Fast forward to the present. SpinRite, authored by Steve Gibson of Gibson Research Company, remains widely regarded as one of the pre-eminent tools for testing of hard drives.

Now in its sixth release, the latest iterations of SpinRite don't just fix problems; they help detect problems before they occur.

SpinRite works by obtaining low-level access to storage devices. This access allows SpinRite to detect and fix serious problems on x86 systems (and on the Macintosh, when its storage is temporarily relocated or accessed via a PC). The application goes far beyond looking at file integrity, which is where applications like Windows ScanDisk focus primarily. In addition to warning users about problems before they occur, SpinRite can examine and repair defects in the magnetic media itself -- and even attempt to recover data lost because of a media defect. SpinRite also restores diskettes.

Another key feature of SpinRite is that it's unlikely to damage data in the process of recovering it. Defects in a particular area of a drive are addressed only after the program has "lifted" all the data from that area for safekeeping. Once the damaged areas have been identified, the "good" data is returned to safe portions of the drive. That way, there's a far lower likelihood that good data is lost when SpinRite marks the damaged areas as unusable.

Version 6.0 debuted last year and supports FAT, NTFS, Linux, Novell, and a number of other file systems, as well as multi-OS drives and unformatted disks.