How to fix Windows update error 0xc1900131?

Error 0xc1900131 stops a Windows version upgrade, such as 23H2, 24H2 or 25H2, after the download. Microsoft lists it as MOSETUP_E_INSTALL_HASH_MISMATCH: "The install cannot continue because the instance hash does not match." Remove the files left by the earlier attempt first, so Setup starts again from a clean copy.

Facts checked on 15 October 2026. Steps written for Windows 11 25H2 and 26H2 feature updates, Windows 10 22H2.

What error 0xc1900131 means

Microsoft's table of modern setup error codes gives 0xc1900131 a single line: MOSETUP_E_INSTALL_HASH_MISMATCH, "The install cannot continue because the instance hash does not match." A hash is a short fingerprint of data. Setup compares the fingerprint of the install it is about to finish with the one it recorded, and they differ.

Microsoft does not say what exactly the "instance" is, and we could not confirm it. In practice the code shows up after the download, when Setup is ready to install. That is why the reader above saw the update download fine and then fail.

Why the upgrade fails with 0xc1900131

The code says that two copies of the same thing differ. So the causes are the ones that leave Setup with a mixed or damaged set of files. Each cause points to a fix.

Where the setup logs show what failed

You do not need the logs for Fix 1 to Fix 3. Read them first if you want to know which file did not match, or if you plan to contact support, because Fix 1 deletes them.

The $WINDOWS.~BT folder is hidden. Paste the path into the address bar of File Explorer to open it, and copy the Panther folder to your desktop before you run Fix 1.

How to fix Windows update error 0xc1900131

Fix 1 and Fix 2 remove what Setup compares and solve the error for most readers. Fix 3 installs the new version from a fresh download. Fix 4 makes room. Fix 5 to Fix 7 repair Windows Update and Windows itself and come last.

Fix 1. Restart and delete the files of the earlier upgrade attempt

10 to 15 minutesLow riskEveryone, and first of all readers whose upgrade failed or was cancelled before.

Setup keeps a prepared upgrade in hidden folders on drive C. If those files come from an earlier attempt, they can differ from what the new attempt recorded, which is exactly the mismatch the code names. A restart finishes any pending cleanup, and Disk Cleanup removes the rest so Setup builds a new set.

1. Copy C:\$WINDOWS.~BT\Sources\Panther to your desktop if you want to keep the setup logs.
2. Select Start > Power > Restart. Use Restart, not Shut down, so a pending cleanup can finish.
3. Type Disk Cleanup in the search box and open it. Choose drive C: and select OK.
4. Select Clean up system files, choose drive C: again and select OK.
5. Tick Temporary Windows installation files, Windows upgrade log files and Windows Update Cleanup if they are in the list.
6. Select OK, then Delete Files, and wait until Disk Cleanup closes.
7. Restart the PC once more and open Settings > Windows Update. Select Check for updates.

Fix 2. Reset the Windows Update cache so the upgrade downloads again

10 minutes, plus the new downloadLow riskThe upgrade comes through Settings > Windows Update and Fix 1 did not help.

Windows Update keeps what it downloaded in C:\Windows\SoftwareDistribution and the signatures in catroot2. If that download is damaged, Setup builds a mismatched install from it on every retry. Renaming both folders forces a clean, complete download.

1. Open Command Prompt as administrator. Type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.
2. Stop the update services. Type the commands below and press Enter after each one. If Windows says that other services depend on Cryptographic Services, it stops them too. A message that a service is not started is fine.

   net stop wuauserv
   net stop bits
   net stop cryptsvc

   

3. Delete the download queue files. This clears the list of downloads that the Background Intelligent Transfer Service keeps. If Windows says it cannot find the files, continue.

   del "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\qmgr*.dat"

4. Rename the update cache folders. Renaming keeps a copy in case you need it; Windows creates new, empty folders when the services start again. If you get Access is denied, a service is still running: repeat the previous step.

   ren %systemroot%\SoftwareDistribution SoftwareDistribution.old
   ren %systemroot%\System32\catroot2 catroot2.old

   

5. Start the services again. Type the commands below and press Enter after each one. The requested service has already been started is fine: Windows started it on its own.

   net start cryptsvc
   net start bits
   net start wuauserv

   

6. Restart and check for updates. Restart the PC. Then select Start > Settings > Windows Update > Check for updates. The first check can take longer than usual because everything is downloaded again.

These steps were written for Windows 11 and Windows 10 (the steps are the same). The full page with the other versions and what each result means: Reset Windows Update components

• Restart the PC after the services are started again.
• Open Settings > Windows Update and select Check for updates. The feature update downloads again from zero.
• Keep the PC plugged in, awake and online until it asks for a restart.

Fix 3. Install the new version from a fresh ISO or the Installation Assistant

1 to 2 hoursLow riskYou ran Setup from an ISO, a USB stick or the Installation Assistant, or Fix 1 and Fix 2 did not help.

A damaged or older copy of the setup files gives Setup an image that does not match. A new download straight from Microsoft brings a complete set of files, and Setup records a new instance from it.

1. Back up your important files first: Back up your files (Windows Backup, File History, Time Machine).
2. Delete the old ISO file and any old Windows11InstallationAssistant file from your Downloads folder.
3. Open Microsoft's Download Windows 11 page in a browser.
4. Under Windows 11 Installation Assistant, select Download Now and run the new file. Or download the Windows 11 Disk Image (ISO) again.
5. For the ISO, right-click the new file, select Mount, and double-click setup.exe on the new drive.
6. Choose to keep personal files and apps, and let Setup run with the PC plugged in.
7. After the last restart, open Settings > Windows Update and install the remaining updates.

Fix 4. Free up at least 20 GB on drive C

15 to 30 minutesLow riskDrive C has less than 20 GB free, or Setup has failed with space errors before.

Microsoft asks for at least 20 GB free to upgrade 64-bit Windows and 16 GB for 32-bit. When the drive fills up while Setup prepares the install, it can be left with an incomplete set of files that no longer matches.

1. Open File Explorer > This PC and check the free space on drive C.
2. Empty the Recycle Bin and move large videos or old downloads to another drive.
3. Uninstall apps you no longer use in Settings > Apps > Installed apps.
4. If the PC has a small drive, connect a USB drive. Setup can use it during the upgrade.
5. Run Fix 1 again, then check for updates.

With Storage Sense and screenshots: Free up disk space and delete temporary files

Fix 5. Run the Windows Update troubleshooter

5 minutesNo riskThe upgrade comes through Windows Update and Fix 1 to Fix 4 did not help.

It checks the Windows Update services and their settings, which a cache reset does not. It cannot repair the setup image itself, so it comes after the specific fixes.

1. Open Troubleshoot settings. Select Start > Settings > System > Troubleshoot.
2. Open the list of troubleshooters. Select Other troubleshooters.

   

3. Run the Windows Update troubleshooter. Under Most frequent, select Run next to Windows Update. The Get Help app opens and starts the checks.

   

4. Read the result. Wait until Get Help finishes. If it found and fixed a problem, it says so and asks whether this solved the problem. Answer the question so it can offer the next step.

   

5. Restart the PC. Restart when the troubleshooter finishes, even if it does not ask you to.
6. Check for updates again. Select Start > Settings > Windows Update > Check for updates, and install the updates it finds.

These steps were written for Windows 11 (screenshots: 26H2). The full page with the other versions and what each result means: Run the Windows Update troubleshooter

On Windows 11 the troubleshooter opens in the Get Help app. On Windows 10 22H2 it is under Settings > Update & Security > Troubleshoot > Additional troubleshooters.

Fix 6. Reinstall the current Windows 11 version with Fix problems using Windows Update

1 hour or moreLow riskWindows 11, and the error stays after Fix 1 to Fix 5.

This recovery option downloads a fresh copy of the version you have now and reinstalls it, keeping apps, files and settings. A clean base often lets the next feature update install.

1. Open Settings > System > Recovery.
2. Next to Fix problems using Windows Update, select Reinstall now.
3. Choose whether the PC may restart on its own, then select OK.
4. Keep the PC plugged in and online until it restarts and finishes.
5. Open Settings > Windows Update and check for updates again.

More options, including Reset this PC: Reinstall Windows without losing files

Fix 7. Repair Windows system files with DISM and SFC

20 to 40 minutesLow riskOther updates fail too, or every fix above failed.

DISM repairs the component store that updates install into, and SFC then repairs protected system files from it. Damaged system files can make Setup fail its checks again and again.

1. Open an elevated command window. Right-click Start and select Terminal (Admin), or type cmd in the search box, right-click Command Prompt and select Run as administrator. Select Yes when Windows asks for permission.

   

2. Run DISM first. Type the command below and press Enter. DISM downloads clean copies of damaged components from Windows Update, so it can take several minutes. Wait until it says The operation completed successfully.

   DISM.exe /Online /Cleanup-Image /RestoreHealth

   

3. Run System File Checker. In the same window, type the command below and press Enter. Do not close the window until the verification reaches 100%.

   sfc /scannow

   

4. Read the result and restart. Compare the last message with the table below this guide, then restart the PC so that repaired files are loaded.

   

These steps were written for Windows 11 24H2 and 25H2. The full page with the other versions and what each result means: Run DISM and SFC to repair Windows system files

If error 0xc1900131 is still there

When the error comes back after clean files, a fresh ISO and a system repair, the setup logs decide the next step. Collect them right after the failure, before the next try overwrites them.

• What to send to support: the code 0xc1900131, the version you tried to install, and your current version from Settings > System > About.
• Attach setupact.log and setuperr.log from C:\$WINDOWS.~BT\Sources\Panther.
• Say which fixes you already tried and whether you used Windows Update, the Installation Assistant or an ISO.

How to keep 0xc1900131 from coming back

Frequently asked questions

What does error 0xc1900131 mean?

It means Windows Setup stopped an upgrade because the prepared install does not match what it recorded. Microsoft's setup error table names it MOSETUP_E_INSTALL_HASH_MISMATCH: "The install cannot continue because the instance hash does not match." Microsoft does not explain the instance hash further. In practice, leftovers of an earlier attempt or a damaged download are behind it. Your files are not changed. Start with Fix 1.

What does Install error - 0xc1900131 in Windows Update mean?

It is the same error, shown in Settings > Windows Update next to the feature update. "Install error" tells you the download finished and the failure came when Windows tried to install it. Pressing Retry usually reuses the same prepared files, so the code comes back. Restart, delete the temporary Windows installation files with Disk Cleanup (Fix 1), reset the update cache (Fix 2), then check for updates again.

Is 0x1900131 the same error?

Yes. 0x1900131 is 0xc1900131 with the letter c dropped, usually a typing slip. Windows always shows the full code, 0xc1900131 or 0xC1900131, and the case of the letters does not matter. Every fix on this page applies. If you see a different code, such as 0xc1900101 or 0xc1900130, look it up by its exact digits, because each code in this group has its own meaning.

What is the difference between 0xc1900131 and 0xc1900130?

Both come from the same part of Windows Setup. 0xc1900130, MOSETUP_E_INSTALL_HASH_MISSING, says the instance hash was not found. 0xc1900131 says it was found but does not match. Either way Setup cannot confirm that the prepared install is the one it expects. The fixes are the same: remove the old upgrade files, download again and, if needed, install from a fresh ISO.

Does 0xc1900131 mean my PC cannot run Windows 11?

No. Compatibility problems have their own codes in Microsoft's table, such as 0xC1900200, "The system does not pass the minimum requirements to install the update." 0xc1900131 is about the install files, not the hardware. If Windows Update offered you the version, it considers the PC eligible. Clean up and download again. If the error keeps returning on one PC, check the drive and memory as described above.

Will deleting the temporary Windows installation files remove my files?

No. Temporary Windows installation files, Windows upgrade log files and Windows Update Cleanup hold only setup and update data. Your documents, photos, apps and settings are not in them. The one thing you lose is the setup logs, so copy the Panther folder first if you want them. Windows creates new setup files when the upgrade starts again.

Should I scan for malware because of 0xc1900131?

It is not a typical sign of malware, and no source we read ties this code to an infection. A mismatch after an interrupted or damaged download is far more likely. A full scan with Microsoft Defender does no harm if the PC also shows other strange behaviour: How to scan for malware with Microsoft Defender. Otherwise start with the fixes on this page.

Can I just keep pressing Retry until it works?

It rarely helps. Each retry starts from the files Setup already prepared, and those are the ones that do not match. One restart is worth it, because it lets Windows finish a pending cleanup from the earlier attempt. After that, remove the old files with Fix 1 and reset the cache with Fix 2. If the error stays, a fresh ISO in Fix 3 avoids the stored files completely.

I have done everything and it still does not work. What now?

This also answers the Spanish search "ya he hecho todo y no funciona". Copy setupact.log and setuperr.log from C:\$WINDOWS.~BT\Sources\Panther, then download the ISO again on another network and run Setup from it. If it still fails, read the first error in setuperr.log, check the drive with chkdsk and test the memory. Send the logs to Microsoft support or your IT department.

This page came up for a search about something else. Is it the right one?

This page is only about Windows Setup error 0xc1900131. It is not about duplicate image finders or other tools, so if you searched for one of those, this guide will not help with it. If you typed a short question such as "how to fix this problem" and see 0xc1900131 on your screen, the short answer at the top and Fix 1 are where to start.