My computer won't start; I have Windows 8 and error code 0xc000007b

I need some help; I'm locked out of my computer. I reach the Dell sign, then it says this :

Your PC needs to be repaired

The Operating system couldn't be loaded because a critical driver is missing or contains errors

File: \windows\system32\DRIVERS\avgmfx64.sys

Error Code: 0xc000007b

I'm so confused on how to fix it, any assistance will be useful

P.S: I'm writing this on my brother's computer, I can't load past the Dell logo.


Question Info

Last updated August 21, 2018 Views 455 Applies to:


Thank you for posting your query on Microsoft Community.

As per description, you are unable to start your computer.

In first place, I would suggest you to use Windows 8 installation DVD and run Automatic repair to repair boot files. If you don’t have an installation DVD, refer to the link to create one on some other computer:

“Let us try to create Windows 8 installation media (DVD or USB). Refer the following link.

How to create installation media for a PC refresh or reset:


Contact your computer manufacture for the product key.

Once you have bootable DVD or USB drive for windows 8, I would suggest you to perform following method and check if it helps.

Method 1: Perform Automatic Repair using installation Media

Follow the steps to perform Automatic Repair:

  1. Insert the media such as (USB or DVD) and restart the computer.

  2. Press F12 key (typically this is F12, but it can differ between computer manufacturers) and choose the drive that you inserted the installation media into.

  3. Once the Windows Setup window appears, follow these steps:

  4. Click Next and select Repair your computer.

  5. You will then see a blue screen and an option to choose.

  6. Choose the option Troubleshoot and select Advanced options.

  7. You may choose Automatic Repair from Advanced boot option.


If issue still persists try method 2


Method 2: Perform a system restore using Windows 8 Installation Media 

Perform a system restore using Windows 8 Installation Media and check if that helps.

  1. Insert the installation DVD or USB and boot Windows 8 from it.

  2. In the ‘Windows setup’ page select the ‘language to install’, ‘Time and currency format’ and the ‘keyboard or input method’ and click on ‘next’.

  3. Click on ‘Repair your computer’ and select ‘Troubleshoot’.

  4. Click on ‘Advanced options’ and select ‘System Restore’ and select the operating system.

For further reference, you may refer to the following Microsoft Help article.

Important: When you use System Restore to restore the computer to a previous state, programs and updates that you installed are removed.

Hope this information is helpful. Please do let us know if you need further assistance with Windows.


Ashish Sondhi

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