Get the fix to 0xc0000001 boot error for the following Windows versions: XP, Vista, 7, 8 or 8.1.

Alternative Info messages below “Status: 0xc0000001”:

The most common Info message is probably “A required device isn’t connected or can’t be accessed”, but your computer can also show these alternatives:

  • The boot selection failed because a required device is inaccessible
  • The application or operating system could not be loaded because a required file is missing or contains errors
The 0xc0000001 Windows Error

0xc0000001 Windows Error

Sample 0xc0000001 Error in Windows Vista, 8 or 8.1

Different Windows versions show different screens that refer to same error. Here is how this boot error looks in Windows Vista, where the Info message is related to a required device:

Windows Boot Manager

Windows failed to start. A recent hardware or software change might be the cause. To fix the problem:

1. Insert your Windows installation disc and restart your computer.
2. Choose your language settings, and then click "Next."
3. Click "Repair your computer."

If you do not have this disc, contact your system administrator or computer manufacturer for assistance

Status: 0xc0000001

Info: A required device isn't connected or can't be accessed.

How it looks in Windows 8 or Windows 8.1 with the same Info message:

Windows Recovery Environment

Your PC couldn't start properly

A required device isn't connected or can't be accessed.

Error code: 0xc0000001

You'll need to use the recovery tool on your installation media. If you don't have any installation media like disc or USB devices, contact your system administrator or PC manufacturer.

Other Windows 8 users reported a “After multiple tries, the operating system or your PC failed to start, so it needs to be repaired.” line in the above screen.

Fix: Use Easy Recovery Essentials

Easy Recovery Essentials can fix many errors such as this automatically using its built-in Automated Repair option. EasyRE is currently available for Windows XP, Vista, 7 and 8 and can be downloaded and created on any PC.

  1. Download Easy Recovery Essentials. Make sure to note your Windows version (XP, Vista, 7 or 8) before you download EasyRE. This guide can help you identify what version of Windows you have installed.
  2. Burn the image. Follow these instructions on how to burn the bootable ISO image very carefully, as making a bootable CD can be tricky! Alternatively, these instructions explain how to create a bootable EasyRE recovery USB stick/drive.
  3. Boot up your PC from the Easy Recovery Essentials CD or USB you created.
  4. Once EasyRE is running, choose the “Automated Repair” option and click Continue.
    EasyRE Home

    Choose “Automated Repair” in Easy Recovery Essentials

  5. After EasyRE scans your computer’s drives, identify and select the drive letter for your Windows installation from the list, and then click on the Automated Repair button to begin.
    EasyRE displays a list of found Windows operating systems

    Choose the drive associated with the Windows installation you’re trying to repair.

  6. Easy Recovery Essentials will start analyzing the selected drive for problems. EasyRE will test for and attempt to automatically correct errors with the disk, partition, bootsector, filesystem, bootloader, and registry. No intervention is required, as EasyRE’s repair is fully automated:
    EasyRE: Automated Repair

    Easy Recovery Essentials searches for errors and makes corrections to the selected Windows installation.

  7. Once the process is complete, EasyRE will report its findings. Click on the Restart button to reboot your PC and test the changes.
  8. The “0xc0000001” error should now be fixed as your PC begins to load:
    EasyRE: Automated Repair

    Windows, booting up successfully.

You can download Easy Recovery Essentials from here.

Fixes for 0xc0000001 in Windows XP

Windows XP users will most likely see a message like this:

Security Accounts Manager initialization failed because of the following error: A device attached to the system is not functioning.

Error Status: 0xc0000001.

Please click OK to shut down this system and reboot into Safe Mode, check event log for more detailed information.

This is because the SAM file is corrupted or missing. SAM stands for Security Accounts Manager.

The fix for this is to replace or restore the SAM file.

Fix #1: Copy the SAM File from the Repair Folder

If you’re able to login into Windows, copy the file from C:\WINDOWS\repair to C:\WINDOWS\system32\config. The steps are simple:

  1. Copy the SAM file from C:\WINDOWS\repair
  2. Paste that file to C:\WINDOWS\system32\config

This will remove all login credentials your Windows copy has, including username and password and revert back to the original username that was added when you installed Windows.

Fix #2: Check RAM

Check if you recently added any new RAM modules. Users have reported that a new RAM module was the actual cause for this boot error.

Fixes for 0xc0000001 in Windows Vista

Windows Setup CD/DVD Required!
Some of the solutions below require the use of the Microsoft Windows setup CD or DVD. If your PC did not come with a Windows installation disc or if you no longer have your Windows setup media, you can use Easy Recovery Essentials for Windows instead. EasyRE will automatically find and fix many problems, and can also be used to solve this problem with the directions below.

Fix #1: Run chkdsk

  1. Insert your Windows install disc and restart your computer
  2. Press any key when the message appear to boot from your install disk
  3. When in the Microsoft Setup Menu, press R to open the Recovery Console
  4. Enter your Administrator password
  5. Enter the following command when command prompt appears:
    chkdsk c: /F

    where C: is your hard disk drive’s letter (can be different from C: used here)

  6. Press Enter

If Command Prompt shows errors after running the above command, run it again until it shows no errors.

Fix #2: Check RAM

Check the RAM your computer has. Similar to the fix for Windows XP systems above, check if you recently added any new RAM modules.

Users have reported that a new RAM module was the actual cause for this boot error.

Fix Status: 0xc0000001 in Windows 7

Windows Setup CD/DVD Required!
Some of the solutions below require the use of the Microsoft Windows setup CD or DVD. If your PC did not come with a Windows installation disc or if you no longer have your Windows setup media, you can use Easy Recovery Essentials for Windows instead. EasyRE will automatically find and fix many problems, and can also be used to solve this problem with the directions below.

Fix #1: Run sfc /scannow

A sfc /scannow (sfc stands for System File Checker) command will scan all protected files of Windows and will try to replace incorrect, corrupt, changed or damaged versions with the correct versions.

Here are the steps to run sfc at boot:

  1. Boot from the install CD
  2. Select your language, time and keyboard method
  3. Select Repair your computer
  4. Select your operating system when the “System Recovery Options” box appears, but note down the drive’s letter (F:, G: etc.). In our example this will be D:
  5. Select Command Prompt
  6. Type the following command with your hard drive’s letter:
    sfc /scannow /offbootdir=d:\ /offwindir=d:\windows
  7. When scanning is complete, type exit to quit the Command Prompt:
    exit
  8. Press Enter

Fix #2: Check RAM

Check the RAM your computer has. Make sure you haven’t added any new modules for your RAM.

Try to either remove them all and leave just 1 module or replace them entirely.

Fix 0xc0000001 in Windows 8 or 8.1

Windows 8 or 8.1 users may fix this boot error without an installation disc by using the Windows Startup Settings (see Fix #1 below).

Fix #1: Use Windows Startup Settings

  1. Restart your computer
  2. Press SHIFT + F8 when booting to open the Recovery screen
  3. Select the Advanced repair options
  4. Go to Troubleshoot and then Advanced Options
  5. Select Windows Startup Settings
  6. Click Restart

More Information

Linked Entries

Support Links

Applicable Systems

This Windows-related knowledgebase article applies to the following operating systems:

  • Windows XP (all editions)
  • Windows Vista (all editions)
  • Windows 7 (all editions)
  • Windows 8 (all editions)
  • Windows 8.1 (all editions)