CHKDSK: Understand Your Computer

CHKDSK (present in all versions, useful in 2000 and XP only)
CHKDSK is a program used for checking the status of magnetic drives/disks, fixing certain errors, and even recovering readable data from bad disk sectors. It isn't particularly useful in 9x, except for obtaining a report on files on the disk. To correct any disk errors on 9x, run ScanDisk. In 2000, and XP, CHKDSK replaces 9x's ScanDisk. In 2000 and XP, it is easier to run CHKDSK from Windows, so you might as well save the command-line version for when the computer is booted into Safe Mode, Command prompt only. When invoked with the /f and/or /r switches to run on a disk in use, CHKDSK will prompt you to run at the next boot.
Use
Type CHKDSK followed by the drive letter and colon (:), followed by any switches (each switch must be preceded by a space character).
Switches
/c: Use with NTFS-formatted drives only. Skips folder structure cycle checking, resulting in a faster completion.
/f: Fixes file system errors on the disk. If run on a disk currently in use, /f causes CHKDSK to be run on the next boot.
/i: Use with NTFS-formatted drives only. Performs a less exhaustive check of index entries, resulting in a faster completion.
/r: Recovers readable information from bad disk sectors. If run on a disk currently in use, /r causes CHKDSK to be run on the next boot. See the listing for the RECOVER command for another tool that can recover lost data.
/v: Displays the name of each file in every folder as the disk is checked.
/x: Use with NTFS-formatted drives only. Makes all necessary changes to any network-mapped drives in order for CHKDSK to work on them. /x also includes the functionality of the /r switch.
Notes
· Running CHKDSK without the /f, /r, and/or /x switches is usually pointless and might report false disk errors.
· If you are prompted to convert lost chains (unidentified file fragments) to files, do so by typing . You can then find the files in the root folder (C:\ in the C: drive). The files are named File****.chk (the asterisks stand for any character). If the files don't contain any data you need, you can delete them. If you type (answer no) to the prompt, the fragments will be deleted automatically.If you use the /f or /x switch on a very large disk such as 80GB, or one with huge numbers of files (e.g., millions of files), CHKDSK might take several days to complete. CHKDSK cannot be stopped while it is running, so the computer will not be available for this time.