how chkdsk command works?
Checkdisk is a command in DOS and Microsoft Windows systems which verifies a hard disk or a floppy disk for file system integrity. It is similar to the fsck command in Unix. By default, CHKDSK neither fixes errors nor checks for bad sectors. In order to fix errors while using the command line interface, the /F parameter should be specified. In order to check for and mark bad sectors, the /R parameter should be specified. Other parameters can be listed by typing the command chkdsk