Bypass CONFIG.SYS and AUTOEXEC.BAT in MS-DOS 6.22

Bypassing CONFIG.SYS and AUTOEXEC.BAT during startup is a standard troubleshooting method in MS-DOS 6.22. This process, commonly known as performing a "Clean Boot," allows users to load MS-DOS without any device drivers, memory managers, or startup programs. It is an essential technique for diagnosing boot errors, freeing up conventional memory, or isolating faulty hardware drivers that cause the operating system to hang.

Method 1: Perform a Clean Boot (Complete Bypass)

To completely skip both CONFIG.SYS and AUTOEXEC.BAT:

  1. Turn on or restart your computer.
  2. Watch the screen closely until you see the text: "Starting MS-DOS..."
  3. Immediately press the F5 key, or press and hold the Shift key.

Once pressed, MS-DOS displays the message: MS-DOS is bypassing your CONFIG.SYS and AUTOEXEC.BAT files.

The system will then boot straight to the standard command prompt (C:\>) without loading any drivers (such as HIMEM.SYS or mouse drivers) or environment variables defined in your startup files.

Method 2: Perform an Interactive Boot (Selective Bypass)

If you need to bypass only specific problematic drivers while keeping others active, you can use the interactive boot method:

  1. Restart your computer.
  2. When the "Starting MS-DOS..." prompt appears, press the F8 key.
  3. MS-DOS will prompt you line-by-line for every command inside CONFIG.SYS.
    • Press Y to load the specific driver.
    • Press N to bypass the specific driver.
    • Press Esc to accept all remaining prompts as "Yes".
  4. After processing CONFIG.SYS, the system will ask: Process AUTOEXEC.BAT [Y/N]?
    • Press N to skip the entire file, or press Y to step through each command line-by-line.

Important Notes on Timing

The window to press F5 or F8 lasts roughly two seconds by default. If your system loads past the "Starting MS-DOS..." prompt before you press the key, press Ctrl + Alt + Del to restart and try again immediately as the memory check finishes.