A utility for locating, reporting, and correcting file system errors (such as lost file fragments and cross-linked files) on disks. Scandisk was originally included in version 6.2 of the MS-DOS operating system, but there are also versions for Microsoft Windows 95 and Windows 98. Scandisk is generally preferable to chkdsk because it has better error recovery features and can perform a more exhaustive surface scan if needed.
It is a good idea to run scandisk regularly on your system because it is easier to prevent data loss due to hard drive problems than to fix it afterwards. Scandisk creates a log called scandisk.log, which you can view to find out what problems were found and what corrective actions were performed.