When Windows OS fails to detect the controller driver or any other boot critical drivers, it fails to boot with stop code 0x0000007b and in the bracket, you would see 0x and the last two digits would be 34. The second parameter of the code here is important. 0x34 means the system is unable to load controller drivers. The drivers could be either corrupt, missing or altered by some third party applications. Since the controller driver required to detect bootable device could not be loaded, the stop error code 0x0000007b means inaccessible boot device. Steps to fix Windows blue screen error code 0x0000007b are mentioned below:
- Whenever you get c, try running check test. The reason behind this is running a check test repairs the block where the controller driver is located on the disk and makes it available to the system to load it again.
- If running check test doesn’t help the situation, then boot the OS into windows recovery mode using windows 7 and above bootable media. The bootable media could be any client or server windows hosts from windows vista or windows server 2008.
- So once you enter the bootable media, press any key to start the system using a CD or DVD.
- On the next screen, select next without changing any options.
- On the install now screen, click on repair your computer. On the next screen, check if your correct OS is listed and also note down the location of the disk where the OS is installed.
- Click next and then you will see System Recovery Options. Click on command prompt and load the command prompt in the memory.
- Type Regedit and hit enter to open the registry. The registry that you see is not the actual registry of the server, instead, this registry is loaded from the booted media with default options.
- So we need to load the system hive of the server. To do this click on HKEY local machine and then click on load hive.
- Go to file and select load hives and click on the computer icon. Now, remember that earlier you made a note of the location where your OS is installed.
- Click on the drive where OS is installed and then navigate to windows system 32 config.
- Under config. you can see all your registry hives, sam, security, software, and system.
- As we need to check if there is any third party driver causing this 0x0000007b error code, we will select the system hive. System hive stores all the drivers and boot related information since this is the hive that is loaded first during the boot process for drivers to initialize.
- Click on system and hit open and give any random name to this hive.
- Now expand the HKEY local machine and select test. Expand test and click on the select hive. Under select, check the value against default control set and select it. The drivers and the application to load it is stored under the control set. So the default control set will be loaded every time. In case you know that your default control set is corrupt, you can load the backup control set.
- Expand the selected control set and then expand control and then expand class.
- Expand the class as well. Here you will see all the default filter drivers. If any third party driver interferes with them, the OS fails to boot and gives a blue screen and a 0x0000007b error code.
- These filter drivers are located under the keys that start from 4d36e965 to 4d36e980. Check all these filter drivers one by one and check for values in front of the upper filters. you may not know the default values, so compare these values with your working machine to understand if they are as expected or they have been tampered.
- If any upper filter has been tampered with, you will see an additional entry as “styn typ”. This is not expected.
- To solve this problem, double click on the upper filter and clear the additional entries. Do this for all the filters.
- If you don’t find any extra entry, then click on test hive again and select unload hive from file option.
- Close the registry and command prompt to reboot the server. Let the server boot and see the result.