Windows Surface Scanner is a free, fast utility that scans your hard drive(s) for physical errors. It will examine each sector on your hard drive for read errors and reports them if found. It is purely diagnostic and will not fix or “mark” bad sectors or recover data. The main reason why you would use this is for a quick diagnosis – it is considerably faster than Windows’ built in checker and the scan can be performed from within Windows without a reboot. However, it does not have a “repair” bad sectors option which the Windows utility offers.