How to Fix It When A Disk Read Error Occurs

Windows error recovery troubleshooting

How to fix it when a disk read error occurs

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When there is a hard drive or partition issue in Windows, a warning stating, "a disk read error occurred" may appear. This message is likely followed with instructions to press Ctrl+Alt+Del to restart, which you should do to see if the problem is resolved.

However, if the computer reboots only to display the same error message again and again, troubleshooting the issue is required.

These instructions apply to Windows 10, Windows 8, and Windows 7.

What Causes Disk Read Errors

Although the origin of this error can vary from one computer to the next, there are some common causes, including the following.

Insufficient RAM.
Loose or faulty connections.
A damaged hard drive or boot configuration data store.

How to Fix It When A Disk Read Error Occurs

Walking through potential fixes for frequent reasons for this error could pinpoint and resolve the issue.

  1. Test the RAM. A problem when booting could be the result of problems with the computer's memory. You can use Windows Memory Diagnostic by typing mdsched into the Windows Search (or Start Search) box and pressing Enter. The tool will run automatically when you restart the computer. Alternatively, there are several other free memory test programs you could try.

  2. Replace the RAM or if your system has two RAM modules in the system, try interchanging their slots. In addition, clean any dust off the chips while checking them out in case the grime is interfering.

  3. Check cables. Loose connections or faulty cables can cause issues with booting as well as hard drive errors. Look for disconnected cables. If possible, swap out cables with spares. At the very least, disconnect them, inspect the cables for any damage and then reseat them securely.

  4. Test the hard drive. This could mean removing the hard drive from your current machine and plugging it into a working computer, where you can scan for bad sectors. This could help you determine whether the issue is repairable or if you need a new hard disk drive (HDD) and a fresh install of Windows.

  5. Reset the BIOS. Reverting the BIOS to defaults could resolve the issue. Access the BIOS at startup and look for an option to load BIOS setup defaults, which could be one of the following or similar:

    • Load BIOS Defaults
    • Load Default Settings
    • Load Fail-Safe Defaults

    Alternatively, you could update the BIOS version to the latest available.

  6. Defrag the computer. In certain circumstances, this could fix the issue. Connect the HDD to another machine to perform the defragmentation and then try to boot from it.

  7. When you are unable to start your computer and see a disk read error, the boot configuration data store (BCD) could be corrupt, missing, or incorrectly configured. If this is the problem, rebuilding the BCD could be the solution. In addition, you can use the Bootrec.exe tool to troubleshoot other startup issues. For instance, the fixmbr command allows the repair of a corrupted or damaged Master Boot Record and the fixboot command writes a new partition boot sector.

  8. Rescue data. In some cases, a severely corrupted or failing hard drive might need to be replaced. If this is the case, there might still be hope. It is possible that you could recover files, even if the computer will not start. Although it might take some effort, using a data recovery program could at least save important files that you would hate to lose.