Code 520

[Garry74]

I have a HP elitebook 840G5 i7 8th gen. There is a problem with HP Sure Start. The code is 520. It wants to restart but doesn’t start afterwards. It also says “The operating system couldn’t be loaded because the kernel is missing or contains errors”. The screen got frozed after it restarts every time.

[Raqeeb26]

Hi @Garry74 ,

Welcome to The HP Support Community.

Thank you for posting your query, I will be glad to help you.

Let's fix it step-by-step. You will need another working computer and a blank USB drive (at least 32GB) for Step 2.

Step 1: Resolve the HP Sure Start 520 Error

First, we need to fix the BIOS. The Sure Start error 520 means the Secure Boot keys have been corrupted. Resetting the BIOS to factory defaults will fix this.

1. Hard Power Off: Press and hold the power button on your EliteBook for about 15 seconds until it completely shuts down.

2. Enter BIOS Setup: Turn the laptop back on and immediately start tapping the F10 key repeatedly until the BIOS Setup screen appears.

3. Restore Defaults: Look for an option to "Restore Defaults" or "Load Setup Defaults." This is often on the "Main" or "Exit" tab. Select it and press Enter.

4. Save and Exit: Choose the option to "Save Changes and Exit" (often the F10 key again). Confirm with "Yes."

The laptop will restart. The HP Sure Start error should now be gone, but you will likely still see the Windows kernel error. It's time to fix that.

Step 2: Repair the Windows Operating System

The kernel error means we need to repair Windows using an external tool.

1. Create Windows Installation Media:

   • On another computer, go to the official Microsoft Windows 10 Download page (or the Windows 11 page if you use that).

   • Click "Download tool now" and run the Media Creation Tool.

   • Follow the prompts to create a bootable USB drive.

2. Boot from the USB Drive:

   • Insert the USB drive you just created into your EliteBook.

   • Turn on the laptop and immediately start tapping the F9 key repeatedly to open the Boot Device Options menu.

   • Select your USB drive from the list and press Enter.

3. Use Windows Recovery Tools:

   • The system will load files from the USB. On the Windows Setup screen, choose your language and click Next.

   • Do NOT click "Install now." Instead, look for and click on "Repair your computer" in the bottom-left corner.

   • This will take you to a blue screen with options. Select Troubleshoot.

4. Run Startup Repair:

   • From the Troubleshoot menu, select Advanced options > Startup Repair.

   • Let the process run completely. It will attempt to find and fix the boot issues automatically. If it works, you're done! If not, proceed to the next step.

5. Rebuild Boot Files (If Startup Repair Fails):

   • Go back to Troubleshoot > Advanced options and select Command Prompt.

   • Type the following commands one by one, pressing Enter after each:

     bootrec /fixmbr
     bootrec /fixboot
     bootrec /rebuildbcd
     

   • When bootrec /rebuildbcd asks if you want to add an installation to the boot list, type Y and press Enter.

   • Close the Command Prompt and restart your computer (remove the USB drive).

Step 2: Reinstall operating using HP Cloud Recovery: Here is the exe link  below you can use it:

https://ftp.hp.com/pub/softpaq/sp153001-153500/sp153344.exe

Once  .exe is installed and search hp cloud recovery in windows search bar and run as admin. Follow the setup and pendrive 32GB should be connected as well and once setup installation  is complete , restart the unit with f9 and then select usb and follow instruction for o.s recovery installation. 

What If It Still Doesn't Work?

If after all these steps the computer still won't boot, it could indicate a more serious issue like a failing SSD. Before reinstalling Windows completely, run a hardware check:

• Restart the laptop and immediately tap the F2 key to enter HP PC Hardware Diagnostics.

• Run a memory and storate test  to check for any hardware failures, especially with the storage drive.

This process should get your EliteBook up and running again. The key is to fix the BIOS first, then the operating system.

Hope this helps resolve your issue