How to Check Disk Surface Errors in MS-DOS 6.22

This article explains the dedicated utility used in MS-DOS 6.22 to detect and repair physical hard disk platter defects. You will learn about Microsoft ScanDisk, how it differs from older disk tools, the commands required to perform a comprehensive surface analysis, and how the operating system isolates damaged sectors to prevent data loss.

In MS-DOS 6.22, the utility used to check hard disk platters for surface errors is ScanDisk (SCANDISK.EXE). Introduced by Microsoft in MS-DOS 6.2 to replace the more basic CHKDSK utility, ScanDisk provides comprehensive diagnostic and repair capabilities for both logical file system structures and physical media defects.

How ScanDisk Performs Surface Scans

While CHKDSK primarily verified the File Allocation Table (FAT) and directory tree integrity, ScanDisk includes a dedicated surface scan routine. During a surface scan, the utility performs read and write tests across every cluster on the drive platter. If a sector fails to read or write reliably, ScanDisk flags the cluster containing that sector as "bad" in the FAT. This prevents MS-DOS from attempting to store data in that physical location in the future. If data already resides in a failing sector, ScanDisk attempts to read the data, relocate it to a healthy sector, and mark the defective area.

ScanDisk Commands and Switches

You can run ScanDisk interactively or automate the surface check using command-line arguments:

• Interactive Mode: Typing SCANDISK and pressing Enter launches the full-screen text user interface. After completing the initial file structure tests, the program prompts whether to perform a surface scan.
• Direct Surface Scan: To initiate an immediate surface scan on the primary drive, use the command:

  SCANDISK C: /SURFACE

• Unattended Scan: To scan all local drives, automatically test the surface, and prevent interactive prompts, run:

  SCANDISK /ALL /SURFACE /AUTOFIX /NOSAVE

  • /ALL checks all accessible local drives.
  • /SURFACE forces the physical cluster check without prompting.
  • /AUTOFIX repairs logical and physical errors automatically.
  • /NOSAVE discards lost clusters rather than converting them into files.

ScanDisk operates on FAT12 and FAT16 file systems, supporting standard hard drives as well as DoubleSpace and DriveSpace compressed volumes native to MS-DOS 6.22.