Checks a disk and displays a status report.

CHKDSK [drive:][[path]filename] [/F] [/V]

  [drive:][path]  Specifies the drive and directory to check.
  filename        Specifies the file(s) to check for fragmentation.
  /F              Fixes errors on the disk.
  /V              Displays the full path and name of every file on the disk.

Type CHKDSK without parameters to check the current disk.

Instead of using CHKDSK, try using SCANDISK.  SCANDISK can reliably detect
and fix a much wider range of disk problems.