How to Fix Windows 11 Update Error KB5091573 and Check Update History for Failed Patches

Fix KB5091573 first by checking the failure code, freeing space, restarting Windows Update services, then installing the patch manually if needed. Windows 11 keeps a clear record of failed patches in Update history, and Microsoft also tracks update health and known issues for Windows 11 releases [source: Microsoft]. If KB5091573 keeps failing, do not keep clicking “Retry” forever. That usually wastes time and gives you the same error again.

TLDR: Open Settings > Windows Update > Update history, find KB5091573, and write down the error code, such as 0x800f0922 or 0x80070002. Then run the Windows Update troubleshooter, clear the update cache, and reboot before trying again. For example, if a laptop has only 3 GB free, a cumulative update may fail until you clear at least 10 GB. In a small office with 50 PCs, even a 6% failure rate means 3 machines need manual repair, so checking history early saves a lot of guesswork.

1. Check Whether KB5091573 Really Failed

Start with proof. Windows can show “Something went wrong” while hiding the real reason behind a tiny error code. It drives me crazy that the useful detail is often two clicks deeper than the giant Retry button.

1. Press Windows + I to open Settings.
2. Go to Windows Update.
3. Select Update history.
4. Expand Quality updates or Other updates.
5. Look for KB5091573 and check whether it says Failed to install.

Write down the error code beside it. If you do not see KB5091573, search the page with your eyes, not the Start menu. Windows Update history does not always make failed patches easy to spot.

2. Do the Simple Fixes First

Before using commands, handle the usual blockers. They sound basic, but they solve many update failures.

• Restart the PC: Not shut down. Use Restart, because it reloads pending update tasks.
• Free disk space: Aim for at least 10 GB free on the system drive.
• Unplug extra devices: Remove docks, old printers, and USB drives during the update.
• Pause VPN or third-party antivirus: Some tools block update files or slow downloads.
• Check your time and region: Wrong time settings can break update checks.

After that, go back to Windows Update and click Retry. If KB5091573 still fails, move on.

3. Run the Windows Update Troubleshooter

The troubleshooter is not magic, but it can reset stuck update checks and repair common service problems. It takes about a minute on a normal PC.

1. Open Settings.
2. Go to System > Troubleshoot > Other troubleshooters.
3. Find Windows Update.
4. Click Run.
5. Apply any repairs it suggests.

Restart when it finishes. Then try KB5091573 again. If the install climbs to 100% and fails on reboot, the update files may be damaged.

4. Clear the Windows Update Cache

Corrupt cache files are a classic cause of repeat failures. Clearing them forces Windows to download a clean copy of KB5091573.

Open Command Prompt as administrator. Then run these commands one by one:

net stop wuauserv
net stop bits
net stop cryptsvc
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start cryptsvc
net start bits
net start wuauserv

Now restart the PC. Open Windows Update and try again. Expect the next scan to take longer than usual because Windows has to rebuild its update folders.

5. Repair Windows System Files

If the cache reset fails, check the Windows image itself. Damaged system files can block cumulative updates, including KB5091573.

Open Terminal or Command Prompt as administrator and run:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

Let both finish. The DISM command may sit at one percentage for several minutes. That is normal. When the scan completes, restart and try the update again.

6. Install KB5091573 Manually

If Windows Update keeps failing, use the Microsoft Update Catalog. Search for KB5091573, pick the version that matches your system, then download and run the installer. You can check your system type under Settings > System > About.

If the catalog does not show KB5091573, double-check the KB number. Mistyped KB numbers are common, and some update IDs appear first in preview rings or managed business channels.

7. Read Failed Patch Details Like a Pro

Update history tells you what failed. The error code tells you why. Common examples include:

• 0x800f0922: Often linked to blocked Microsoft servers, VPN issues, or reserved partition problems.
• 0x80070002: Missing or corrupt update files.
• 0x8024402c: Network, proxy, or DNS trouble.
• 0x80070070: Not enough disk space.

If you manage several PCs, keep a small log with the device name, KB number, date, and error code. It feels boring, but it stops repeat work. If three machines show the same code, you can fix the cause once instead of treating each PC like a mystery.

When to Stop and Wait

Sometimes the fault is not your PC. If KB5091573 fails on many devices at the same time, wait 24 to 48 hours and check Microsoft’s update health notes. A bad patch can be paused, replaced, or fixed server-side. Until then, avoid risky registry edits unless Microsoft or your IT team gives clear steps.

For most users, the winning order is simple: check Update history, note the code, free space, run the troubleshooter, clear the cache, repair system files, then install manually. That sequence fixes the usual causes without turning one failed patch into an all-day mess.