Windows operating systems provide the chkdsk command in order to check disks and file systems for logical or physical errors. Without a parameter it will just display the current status of the disk and file system. The “chkdsk /f” is used to fix errors on the disk and file system. The “chkdsk /r” locates the bad sectors.
The “chkdsk /f” commands find and fix logical errors about the disk and file system. But this does not contain the checking physical disk errors which are generally called a bad sector. A bad sector is a physical problem where the disk sector is damaged physically.
The “chkdsk /r” command also runs the “chkdsk /f” command by checking the disk for errors. As an extra check the “chkdsk /r” also checks the disk for the bad sectors which is physical damage.