How can I fix 2026-07 Cumulative Update for Windows 10 KB5099539?

Question

How can I fix 2026-07 Cumulative Update for Windows 10 KB5099539?

Imen 20

I have been stuck in a loop for a couple of weeks now of the update trying to install before shutdown or on startup, before displaying that it could not complete the update. The error code is 0x800f0922. I have tried uninstalling the preinstalled update, pausing updates, reinstalling Windows updates. Does anyone know how to fix this issue without a full windows reinstall?

Ramesh 181.4K Reputation points Volunteer Moderator

2026-07-22T16:01:02.3466667+00:00
Please upload your CBS logs to OneDrive or GoFile.io and post the link here.

The logs are available in the following folder. Copy the following folder to the desktop.

c:\windows\logs\cbs

Zip the folder and share the file on OneDrive or GoFile.io.
Imen 20 Reputation points

2026-07-22T16:07:04.2366667+00:00

Hi,

Here it is:

https://gofile.io/d/2QI0da

Answer accepted by question author

Ramesh 181.4K Volunteer Moderator

Please open an admin Command Prompt window and run these commands one by one:

cmd

mountvol Y: /s

del  /q  Y:\EFI\Microsoft\Boot\Fonts\*.ttf

powershell -command "GCI Y:\  -File -Recurse | Sort Length -descending | Select FullName, Length, Mode -first 10"

dir Y:\

Post the output here.

Imen 20 Reputation points

2026-07-22T17:22:15.5366667+00:00

Here's what it gave me,
Ramesh 181.4K Reputation points Volunteer Moderator

2026-07-22T17:24:15.1466667+00:00
Open Command Prompt as Administrator

Run the following command:

reg add "HKLM\SYSTEM\CurrentControlSet\Control\Bfsvc" /v EspPaddingPercent /t REG_DWORD /d 0 /f

(Post the output.)

Restart Windows to apply the change and then retry installing the update.

Reference:

https://learn.microsoft.com/en-us/windows/release-health/resolved-issues-windows-11-24h2#may-2026-security-update-might-fail-to-install-with-error-0x800f0922
Imen 20 Reputation points

2026-07-22T19:20:49.82+00:00

This was the fix! Thank you very much for your help.
Ramesh 181.4K Reputation points Volunteer Moderator

2026-07-23T02:02:44.74+00:00

You're welcome!

2 additional answers

Your answer

Ramesh 181.4K Reputation points Volunteer Moderator

2026-07-22T16:01:02.3466667+00:00

Please upload your CBS logs to OneDrive or GoFile.io and post the link here.

The logs are available in the following folder. Copy the following folder to the desktop.

c:\windows\logs\cbs

Zip the folder and share the file on OneDrive or GoFile.io.
Imen 20 Reputation points

2026-07-22T16:07:04.2366667+00:00

Hi,

Here it is:

https://gofile.io/d/2QI0da
Imen 20 Reputation points

2026-07-22T17:22:15.5366667+00:00

Here's what it gave me,
Ramesh 181.4K Reputation points Volunteer Moderator

2026-07-22T17:24:15.1466667+00:00

Open Command Prompt as Administrator

Run the following command:

reg add "HKLM\SYSTEM\CurrentControlSet\Control\Bfsvc" /v EspPaddingPercent /t REG_DWORD /d 0 /f

(Post the output.)

Restart Windows to apply the change and then retry installing the update.

Reference:

https://learn.microsoft.com/en-us/windows/release-health/resolved-issues-windows-11-24h2#may-2026-security-update-might-fail-to-install-with-error-0x800f0922
Imen 20 Reputation points

2026-07-22T19:20:49.82+00:00

This was the fix! Thank you very much for your help.
Ramesh 181.4K Reputation points Volunteer Moderator

2026-07-23T02:02:44.74+00:00

You're welcome!

Answer 1

David-M 126.1K Independent Advisor

Hi. I'm David, and I'm happy to help you.

To be able to assist you better, please clarify the following:

Do you have a third-party antivirus installed? (e.g., Kaspersky, McAfee, Avast, etc.) If yes, which one?
Do you have any VPN software installed? (Even if it's not running at the moment) If yes, which one?

Also. What is the current "OS Build" of your Windows 10?

Press "Windows + R", type winver, and click OK.

If you prefer, share a screenshot. Use the shortcut "Windows + Shift + S" to use the screenshot tool.

Be sure to censor your email address if it appears. The Microsoft Q&A is public.

Looking forward to your reply.

Imen 20 Reputation points

2026-07-21T20:02:46.94+00:00

Hi,

To answer your questions, I do not have an antivirus installed. I do have a VPN, Nord VPN, which I don't run while updating.

Here is the build version, Windows 10 Pro

Looking forward to your response.

Imen
David-M 126.1K Reputation points Independent Advisor

2026-07-22T12:32:49.4866667+00:00
Sorry for the delay in reply. I've been offline.

Thanks for the clarifications.

Even when not actively running, third-party VPNs can unintentionally cause strange network behavior, such as preventing a specific service from communicating with the server it needs to reach. This typically occurs due to VPN software updates or shifting network connections.

Therefore, temporarily uninstall NordVPN, restart (not shutdown) your PC, and try updating Windows.

If the same error occurs after uninstalling the VPN, I suggest doing the following:

1 = Run the Windows Update troubleshooter and try to install the update.

https://support.microsoft.com/en-us/windows/windows-update-troubleshooter-19bc41ca-ad72-ae67-af3c-89ce169755dd#WindowsVersion=Windows_11

2 = If it persists, rename the software distribution folders as instructed below:

Open Start and type cmd, right-click on "Command Prompt", and select "Run as administrator".

Run the following commands at the Command Prompt one at a time:

net stop bits net stop wuauserv net stop cryptsvc ren %systemroot%\softwaredistribution softwaredistribution.bak ren %systemroot%\system32\catroot2 catroot2.bak net start bits net start wuauserv net start cryptsvc

After all these commands are completed, close the Command Prompt window, restart (not shutdown) your computer, and then try to update Windows.

3 = If it persists, use the system file checker to repair possible corrupted or missing system files.

Open Start and type cmd, right-click on "Command Prompt", and select "Run as administrator".

Run the following commands at the Command Prompt one at a time:

dism.exe /online /cleanup-image /scanhealth dism.exe /online /cleanup-image /restorehealth dism.exe /online /cleanup-image /startcomponentcleanup sfc /scannow

Note: Pay close attention to the results of the commands. This will help you determine whether the procedure was completed successfully or if there was a problem. If you get any errors, let me know the error message that was displayed.

Then restart (not shutdown) your PC and see if you can update.

4 = If it persists, download and install the update that is having problems manually.

Download the installation package from the link below.

https://catalog.s.download.windowsupdate.com/c/msdownload/update/software/secu/2026/07/windows10.0-kb5099539-x64_f0016a625ac328256041255cd23a42367ca59e33.msu

Source: https://www.catalog.update.microsoft.com/Search.aspx?q=KB5099539

If the problem persists, please let me know, and I will provide another method.

Feel free to ask any questions you may have.
Imen 20 Reputation points

2026-07-22T15:59:27.4533333+00:00

Hi,

Unfortunately none of these solutions fixed the problem, the issues were as follows:

Uninstalling the VPN and performing a restart and attempt to update didn't help.

1 = Windows troubleshooter found no issues

2 = With the administrator cmd, access was denied to both the .bak files

3 = The top three commands ran without issue, sfc /scannow found corrupted files and fixed them

4 = Downloaded the installation package without issue

All these steps were done, with attempts to restart, and update in between each one. However I am still having the problem where the system gets stuck at 97% and rolls back. I would appreciate any further help.

Looking forward to your response.

Imen
David-M 126.1K Reputation points Independent Advisor

2026-07-22T16:40:49.75+00:00

Just to confirm a detail regarding step 4: Did you download the file and run it to install the update, only for the same behavior to occur? Or did you download the file and then try to update again via Windows Update?

Looking forward to your reply.
Imen 20 Reputation points

2026-07-22T17:23:20.1633333+00:00

I downloaded, and then ran the file to update, and the same thing occurred.
David-M 126.1K Reputation points Independent Advisor

2026-07-22T17:48:02.4+00:00
Thanks for the clarification.

In this case, I suggest you perform an In-place Upgrade. This procedure reinstalls Windows, which helps to fix problems.

It's a simple procedure, and you have the option to keep files, settings, and apps. Therefore, all your data is kept.

Here are the steps:

1 = Download the ISO file to perform the procedure:

Access the link below and click "Download now" to download the Media Creation Tool.

https://www.microsoft.com/software-download/windows10

Run the tool and click "Accept" to accept the terms;

Select "Create installation media (USB flash drive, DVD, or ISO file) for another PC" and click "Next";

In the "Select language, architecture, and edition" step, leave the "Use the recommended options for this PC" box checked and click "Next";

In the "Choose which media to use" step, select "ISO file", click "Next", select where to save, and click "Save".

2 = After downloading the ISO, do the following:

Double-click the ISO file to run it.

(After running the ISO, you may need to double-click the "Setup" file to start the procedure.)

On the "Install Windows 10" screen, uncheck "I want to help make the installation of Windows better" and select "Change how Windows Setup download updates";

On the next screen, select "Not right now" and click "Next";

Accept the terms of use;

At the "Ready to install" screen, select "Choose what to keep" and select what you want to keep.

(In this step, select "Keep personal files and apps" so all your data is kept.)

Click "Install" and wait for the procedure to finish. Your computer may restart several times.

The update may be installed during the In-place Upgrade. Therefore, it may no longer appear in Windows Update. Still, check Windows Update for any pending updates and install them.

If you get any errors, please let me know.

Feel free to ask any questions you may have.

Answer 2

P G Birtwistle 0

I'm also having a major problem with 2026-07 Win 10. The update goes through, but on restart I'm sent to what looks like a BIOS screen asking whether I want to boot to Windows Boot Manager or my SSD. Choosing either just sends me back to the same screen. I can't get safe mode or a prompt, so the update has presumably corrupted the boot sector. I've reinstalled Windows 5 times now onto two different SSD's and the same thing happens every time. There are no external devices attached. I'm running a Samsung NP540U3C notebook. Any ideas anyone?

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