A utility used in Microsoft Windows for locating, reporting, and correcting file system errors on disks. There are versions of chkdsk for all Windows platforms as well as for MS-DOS. The versions for Windows NT and Windows 2000 can be used on both file allocation table (FAT) and NTFS volumes. The syntax for the command can be displayed by typing chkdsk/? at the command prompt.
Typing chkdsk c: tells the computer to check the C drive. Note that using the /f switch will force chkdsk to attempt to repair file system errors. The chkdsk command will attempt to lock the disk first, but if the errors are associated with open files, chkdsk will be scheduled to run at the next reboot.
The chkntfs command is a different command that is included in Windows NT 4 (Service Pack 2 or later) and Windows 2000. It allows administrators to exclude specific volumes from having chkdsk /f performed on them by the autochk.exe program after an unexpected reboot.
Running chkdsk /f can result in data loss if chkdsk cannot repair the volume. Either back up your volumes before running chkdsk, or use scandisk instead.