How to fix 'A required device isn't connected or can't be accessed' 0xc000000f
Jul 30, 2025 am 01:11 AMWhen encountering the "A required device isn't connected or can't be accessed (0xc000000f)" error, it is usually caused by the system's inability to access critical devices (such as hard disks). You can troubleshoot and fix them by following the steps: 1. Check whether the hard disk connection is firm, try to replace the SATA interface or data cable, and unplug the peripherals that may interfere with the startup; 2. Use the Windows installation media to enter the command prompt, and run the bootrec /fixmbr, bootrec /fixboot and bootrec /rebuildbcd commands in turn to repair the boot record; 3. Run chkdsk C: /f /r to check and repair disk errors, pay attention to adjusting the disk letters according to the actual system disk; 4. Disable or update the storage controller driver in safe mode, or try to switch RAID mode to AHCI mode to solve the driver compatibility problem. Follow the steps above to resolve this startup error in most cases.
I encountered the error " A required device isn't connected or can't be accessed (0xc000000f) " which usually occurs when starting the Windows system, indicating that the system cannot access critical devices (such as hard disk or system partition), resulting in the inability to boot normally. This problem may be caused by hardware issues, corrupt boot configurations, or driver conflicts.

Here are some common solutions and operation suggestions to help you troubleshoot step by step and try to fix them:
1. Check whether the hardware connection is normal
If you are using a desktop or a removable device, first of all, you need to troubleshoot hardware problems:

- Poor hard disk contact : Turn on the host after shutting down and check whether the SATA or power cord is plugged tightly.
- Replace the interface or data cable : Sometimes there is a problem with the motherboard interface or data cable, you can try changing the SATA port or cable replacement.
- Interference with external devices : Unplug the USB drive, mobile hard drive, printer and other peripherals and restart it. Sometimes these devices will affect the startup process.
If you are a laptop user, it is not recommended to disassemble the machine by yourself. You can try to enter the BIOS to see if the hard disk has been recognized.
2. Use the installation media to repair the boot record
If the hardware is OK, it is likely that the boot record or BCD (Boot Configuration Data) is damaged. This can be fixed by following the steps:

You need a Windows installation USB or CD, and then perform the following operations:
- Insert the installation media and boot from the USB drive
- After selecting the language, click "Repair Computer"
- Go to "Troubleshooting → Advanced Options → Command Prompt"
- Enter the following command in turn and press Enter:
-
bootrec /fixmbr
-
bootrec /fixboot
-
bootrec /rebuildbcd
-
These commands attempt to repair the primary boot record, boot sector, and rebuild the boot configuration database.
3. Check whether the hard disk has bad channels or file system errors
Sometimes the hard disk itself has logical errors or physical bad channels, which can also cause the system to fail to find the device. You can try running disk checking:
Enter at the command prompt:
-
chkdsk C: /f /r
(C: for your system disk)
This command will scan and fix disk errors and needs to be executed after restarting.
Note: If you are not currently in the system (for example, using the installation USB drive to enter the command line), the drive letter may not be C:, and you need to use
diskpart
to view the actual drive letter.
4. Disable or update relevant drivers (especially storage controllers)
Sometimes, some drivers (especially RAID or NVMe drivers) are incompatible with the system, which can cause the system to not recognize the hard disk.
You can try:
- Disable or uninstall drivers under storage controllers in safe mode (such as Intel RST, NVMe Controller)
- Update motherboard chipset driver
- If using RAID mode, try to switch to AHCI mode (make careful operation)
It is best to back up the current settings before switching BIOS settings to avoid other problems caused by incorrect operations.
Basically these common solutions. Although this error seems scary, it can be solved in most cases by fixing the boot or checking the hardware. When encountering uncertainties, don’t blindly operate it, as it is easier to locate problems step by step.
The above is the detailed content of How to fix 'A required device isn't connected or can't be accessed' 0xc000000f. For more information, please follow other related articles on the PHP Chinese website!

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