Quote:
Chkdsk examines disk space and disk use for the file allocation table (FAT) and NTFS file systems. Chkdsk provides information specific to each file system in a status report. The status report shows errors found in the file system. If you run chkdsk without the /f command-line option on an active partition, it might report spurious errors because it cannot lock the drive. You should use chkdsk occasionally on each disk to check for errors.
And an example of what it 'checks' on an NTFS file system: