Stop error (INACCESSIBLE_BOOT_DEVICE) after you reconfigure critical hardware devices

This article helps fix the Stop error code 0x00000007B that occurs after you reconfigure critical hardware devices.

Applies to:   Windows Server 2012 R2, Windows 10 - all editions
Original KB number:   3024175


Consider the following scenario:

  • You are using a computer that is running Windows.
  • The operating system includes two drivers that are configured to load at startup. For example, the system includes driverA.sys and driverB.sys, and you expect both to load at startup.
  • When the computer starts, driverA.sys is used in the boot-up process but driverB.sys is not. Therefore, the system reconfigures the Start Type setting for driverB.sys from Boot Start to Demand Start.
  • You change the computer hardware configuration. For example, you replace the PCI slot on an SAS controller to which the boot-up hard disk drive is attached. After you make this change, a device that is required to start the machine may require driverB.sys, which is now set to Demand Start instead of Boot Start.

In this scenario, the system does not load driverB.sys, and STOP Error code 0x00000007B is generated. When this occurs, you receive the following error message:



This problem occurs because the system does not support a change in the hardware configuration of devices that are boot critical.

The system has a built-in feature to reduce resource consumption by not loading unnecessary drivers. This feature determines whether a specific driver is set to load automatically at system startup but is not required during startup. If the driver is not required at startup, the system may change the driver to a start type of Demand Start.

Because of this feature, drivers that are necessary to start the system under alternative hardware configurations may be set to Demand Start. If the hardware configuration of the system changes, the system may not find the volume that is necessary to start the system. If this occurs, the Stop error that is mentioned in the "Symptoms" section is generated.


To resolve this issue, restart the system in safe mode. In safe mode, any change to a driver's Start Type setting is reversed, and the values are re-created.

More information

For more information about how to troubleshoot Stop error 0x7B, see Troubleshooting a Stop 0x7B in Windows.


This behavior is by design.