Basic Microsoft DOS troubleshooting

Updated: 03/06/2020 by Computer Hope
Windows command line (DOS)

This page gives you a general overview of how to troubleshoot a computer while in MS-DOS or the Windows command line.

Messages encountered during boot

Before following the steps below, make sure that the error you are encountering is not already documented on Computer Hope. You can do this by performing a quick search for the error or by looking through our MS-DOS Q&A section.

  1. Ensure your computer's BIOS settings are correctly configured for the hardware that is installed in your computer. Improper settings in the BIOS may cause errors when first booting an IBM compatible computer. These errors often occur as the computer is first booting and may stop the load process of the computer.
  2. Errors that are encountered during boot are sometimes due to a misconfiguration with the autoexec.bat or config.sys files. We recommend you edit your autoexec.bat and config.sys and look for any abnormalities. Additional information and help with the autoexec.bat and config.sys is available on our autoexec.bat and config.sys page.

Other error messages

If you're experiencing other error messages, it's likely these errors are being caused by the software program you are running or a hardware device you are attempting to utilize. We recommend you see the basic troubleshooting section for your hardware device or software program. If you encounter errors running an MS-DOS command, see the MS-DOS page for information about each of the commands.

Computer running slowly

  1. Make sure your autoexec.bat and config.sys are optimized. Changing the way programs load into memory, remove unnecessary lines, and changing the order of lines in your config.sys to help with improve the speed of your computer. See the autoexec.bat and config.sys page for additional information.
  2. Make sure your computer has at least 50 MB of free hard drive space. If your computer has less than 50 MB free, it may cause the computer to operate more slowly.
  3. Run Microsoft ScanDisk and Defrag on the computer. For additional information and help with these commands, see our ScanDisk and Defrag pages.
  4. From the MS-DOS prompt, type chkdsk /f . If this gives you a bad command or file name error message, type cd\dos and press Enter to get into the DOS prompt and try it again.
  5. Delete all the temporary files and any ScanDisk error files. From the MS-DOS prompt, type del *.tmp to delete all temporary files, then type del *.chk. Once the files are deleted, type cd\dos to get into the DOS directory and delete the *.tmp and *.chk files as done earlier.
  6. Ensure your computer has the latest drivers for the hardware devices installed in your computer.

Issue with hardware device

If you're having difficulties with a hardware device, see the basic troubleshooting section for steps that can be taken to help resolve your hardware issues.


If you are still running into errors or cannot resolve your issue, you can search our web page, or see our on-line help or Q&A sections for additional help. If, after checking these locations, you are still unable to resolve your issue, feel free to contact our support team.

Additional information