How to fix Windows update error 0x80240035?

Windows update error 0x80240035 means the update was found and often downloaded, but Windows Update did not finish processing it. Microsoft names the code WU_E_UPDATE_NOT_PROCESSED. Restart the PC once, make room on drive C and retry before you reset or repair anything.

Facts checked on 15 October 2026. Steps written for Windows 11 (25H2 and 26H2) and Windows 10 22H2.

What Windows update error 0x80240035 means

Microsoft's Windows Update error code list gives 0x80240035 the name WU_E_UPDATE_NOT_PROCESSED. The description reads: "The update wasn't processed." In plain words, Windows Update had the update in its queue, often fully downloaded, but the job of applying it never reached the end.

The code does not name a damaged file or a wrong package. It says the work was left undone. That is why the first fixes clear what keeps the job from finishing (a pending restart, no free space, a stuck service), and only the later ones rebuild the cache or repair Windows.

Why Windows does not process the update

Microsoft gives only the meaning of the code, not a list of causes. In the Microsoft Q&A threads about 0x80240035, the pattern is the same: the download finishes or nearly finishes, the install climbs to about 20 % and stops, and after a while the error appears. The causes below fit that pattern and are ranked by how often they explain it.

How to fix Windows update error 0x80240035

Fixes 1 and 2 remove the usual reasons why an update is left unprocessed and take a few minutes. Fixes 3 to 5 reset the update services and the cache. Fix 6 installs one update by hand. Fixes 7 and 8 repair Windows itself.

Fix 1. Restart the PC and retry the update

5 to 20 minutesNo riskAlways first. Most of all when another update says Restart required, or when you only shut the PC down since the last update.

Windows Update cannot process a new update while an earlier one waits for a restart. Shut down with fast startup does not finish that work, a real Restart does. After it the queue is free and the same update usually goes through.

1. Save your work and plug a laptop into power.
2. Open Start, select the power button and choose Restart. Do not use Shut down for this step.
3. After Windows starts, wait two or three minutes so background tasks can finish.
4. Open Settings > Windows Update. If you see Resume updates, select it.
5. Select Retry next to the failed update, or Check for updates.
6. Leave the PC on and awake until the update says Restart now or finishes.

Fix 2. Free up space on drive C

10 minutesLow riskDrive C has only a few gigabytes free, or the failed update is a version upgrade such as 24H2 or 25H2.

An update is unpacked and staged on drive C before it is applied. When it runs out of room in the middle, the job is left unprocessed. Old update files, temporary files and the Recycle Bin are the safest space to win back.

Use Cleanup recommendations first, then Disk Cleanup with Clean up system files for old update files. Look at what is checked before you confirm, because the Recycle Bin and the Downloads folder can be part of it.

1. Open Storage settings. Select Start > Settings > System > Storage. The top of the page shows how full the drive is and what uses the space.
2. Open Cleanup recommendations. Under Storage management, select Cleanup recommendations.
3. Clean up what Windows suggests. Open each group (Temporary files, Large or unused files, Files synced to the cloud, Unused apps), check the items you do not need and select Clean up in that group.
4. Delete more temporary files. Go back to Storage and select Temporary files. Windows lists the types it can remove with their size. Check the ones you do not need and remove them. Leave Downloads unchecked unless you have checked that folder.
5. Turn on Storage Sense. Back on Storage, turn the Storage Sense switch on. Windows then deletes temporary files on its own when the drive runs low.
6. Choose what Storage Sense cleans. Select Storage Sense to open its page. Check the box for cleaning temporary files, then choose when it runs and how long files may stay in the Recycle Bin and Downloads before they are deleted.
7. Run it now. Select Run Storage Sense now at the bottom of the page.
8. Clean up system files with Disk Cleanup. Type disk cleanup in the search box on the taskbar and open Disk Cleanup. Choose drive C: and select OK, then select Clean up system files and choose C: again.
9. Delete the files. Check the types of files you want to remove (select a name to see what it is), select OK, then Delete files.

These steps were written for Windows 11 (screenshots: 26H2). The full page with the other versions and what each result means: Free up disk space and delete temporary files

Fix 3. Run the Windows Update troubleshooter

5 minutesNo riskFix 1 and Fix 2 did not help, or you prefer an automatic check.

The troubleshooter checks the update services and settings that a failed run can leave in a wrong state and resets them. It is also the first step Microsoft's advisor suggested in the Q&A thread about this code.

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

Fix 4. Restart the Windows Update, BITS and Cryptographic services

5 minutesLow riskEvery retry stops at the same percent, or the troubleshooter found nothing.

After an unfinished job, the services that download, verify and apply updates can stay half-stopped. A restart gives Windows Update a clean start without deleting anything.

Restart these three services, in this order: Windows Update (wuauserv), Background Intelligent Transfer Service (BITS) and Cryptographic Services (CryptSvc). If one is stopped, open its properties, keep Startup type at its default and select Start. Windows Update and BITS are normally Manual, which is fine.

1. Open Services. Press Windows+R, type the command below and press Enter. You can also type Services in the search box on the taskbar and open the app.

   services.msc

2. Find the service. The list is sorted by Name. Click any row and type the first letter of the service to jump to it. Check the Status column (Running or empty) and the Startup Type column.
3. Restart the service. Right-click the service and select Restart. If the service is not running, select Start instead. Wait until the progress window closes.
4. Open its properties to change the startup type. Only if your guide says so: double-click the service. The General tab shows the Service name (used in commands), the Startup type and the Service status.
5. Set the startup type and apply. Choose the type from the Startup type list (Automatic, Automatic (Delayed Start), Manual or Disabled), select Apply, then Start if the service should run now, and OK.

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: Check and restart Windows services

Fix 5. Reset the Windows Update components and cache

15 minutesLow riskThe same KB fails every time, or you see 0x80240031 instead.

A package that was left half-processed stays in the SoftwareDistribution folder, and Windows tries to use it again at every check. Renaming that folder and catroot2 makes Windows download a clean copy and start the job from zero.

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

Fix 6. Install the update by hand from the Microsoft Update Catalog

10 to 20 minutesLow riskOnly one monthly update keeps failing and you know its KB number from Update history.

The catalog gives you the same package as a file, so the Windows Update queue that leaves the job unprocessed is skipped. This works for cumulative updates. A version upgrade such as 24H2 is not in the catalog as one file: use Fix 8 for that.

1. Check your Windows version. Press Windows key + R, type winver and press Enter. Note the version (for example 25H2) and the OS build.
2. Find the KB number. Open Settings > Windows Update. A failed or pending update is listed with its KB number; earlier ones are under Update history.
3. Check the processor type. Open Settings > System > About and look at System type: an x64-based PC needs the x64 file, an ARM-based PC (for example Snapdragon) needs the arm64 file.
4. Search the catalog. Open the Microsoft Update Catalog at catalog.update.microsoft.com in your browser, type the KB number (for example KB5124010) in the search box and press Enter.
5. Pick the right row. Find the row whose title names your Windows version and your processor type (x64-based or arm64-based) and select Download on that row.
6. Download every file listed. A window lists one or more .msu links. Download all of them into one empty folder, for example C:\packages. On Windows 11 24H2 and later the list can include earlier checkpoint updates that the new one needs.
7. Install a single file. If there is only one file, double-click it and confirm the installation in the Windows Update Standalone Installer.
8. Install several files with DISM. If there are several files, open an elevated Terminal or Command Prompt and run DISM with the newest file. DISM finds the other files in the same folder and installs them in the right order.

   DISM /Online /Add-Package /PackagePath:C:\packages\<newest-file>.msu

9. Restart. Restart the PC when the installation finishes, then run winver again: the OS build should have changed.

These steps were written for Windows 11 24H2 and later; Windows 10 22H2. The full page with the other versions and what each result means: Install an update from the Microsoft Update Catalog

Fix 7. Repair system files with SFC and DISM

20 to 30 minutesLow riskSeveral updates fail, also with other codes, or the manual install fails too.

DISM repairs the component store that every update writes into, and SFC repairs the system files. When the store is damaged, Windows Update can start an install and then leave it unprocessed.

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

Fix 8. Reinstall Windows over itself and keep your files and apps

45 to 90 minutesRead the warningNothing above worked, a version upgrade such as 24H2 keeps failing, or 0xC1900101 appears as well.

A repair install replaces all update components at once and puts you on the newest build, so the update that would not go through is no longer needed. In the Microsoft Q&A thread about a 24H2 upgrade that failed with 0x80240035 and sometimes 0xC1900101, this is what solved it.

On Windows 11, start with Settings > System > Recovery > Fix problems using Windows Update > Reinstall now. It downloads a repair copy of your current version. If that fails too, run Setup from the official Windows 11 ISO and choose to keep personal files and apps.

1. Open Recovery in Settings. Open Settings > System > Recovery. Next to Fix problems using Windows Update, select Reinstall now. This keeps your apps, files and settings.
2. Start the reinstall. Choose whether the PC may restart on its own 15 minutes after the installation, then select OK.
3. Wait and restart. Windows Update downloads and installs a repair copy of your current Windows version. Keep the PC plugged in and online, and restart it when asked.
4. If that did not help: Reset PC. Back in Settings > System > Recovery, next to Reset this PC, select Reset PC. This keeps your personal files but removes installed apps and settings.
5. Choose Keep my files. Select Keep my files. Do not select Remove everything.
6. Choose where Windows comes from. Select Cloud download to download a fresh copy of Windows, or Local reinstall to use the files already on the PC (faster, but may not include the latest updates).
7. Reset. Review the summary and select Reset. The PC restarts several times.

These steps were written for Windows 11 22H2 and later. The full page with the other versions and what each result means: Reinstall Windows without losing files

In the Q&A case, the person who fixed it also removed a third-party antivirus and firewall for the time of the upgrade, kept Microsoft Defender on, and disconnected the internet while Setup ran from the ISO. If you do the same, put your security suite back right after: Turn off Microsoft Defender protection for a moment

If error 0x80240035 is still there

When every fix fails, the logs show at which step the update is left unprocessed. Windows writes the update log as trace files. Open PowerShell and run the command below: it builds a readable WindowsUpdate.log on your desktop.

Get-WindowsUpdateLog

If you ask Microsoft Support for help, send the KB number, your Windows version from Settings > System > About, the code 0x80240035 and the lines around it from WindowsUpdate.log. If the PC also freezes, restarts by itself or shows disk errors, check the drive first, because the problem may be hardware: Check a disk for errors (chkdsk)

How to keep error 0x80240035 from coming back

Frequently asked questions

What does error 0x80240035 mean?

It means Windows Update did not finish processing an update. Microsoft's Windows Update error reference lists the code as WU_E_UPDATE_NOT_PROCESSED with the description "The update wasn't processed." It does not prove that the update or Windows is damaged. Most often a pending restart, too little free space or a stuck update service leaves the job unfinished. Restart, free up space and retry first, then reset the update services and cache if the same update keeps failing.

What is "Install error - 0x80240035" in Windows Update?

It is the way Windows Update shows this code when the download finished but the install did not. In the reports we read, the install usually climbs to about 20 or 30 % and stops before the error appears. Restart the PC with Restart, not Shut down, check the free space on drive C and select Retry. If it fails at the same point again, restart the update services (Fix 4) and reset the update cache (Fix 5).

What does 0x80240035(-2145124299) mean?

It is the same error. Some logs, scripts and management tools print the code as a signed decimal number, and -2145124299 is exactly 0x80240035 written that way. So everything on this page applies. If you see it in a script or a management console rather than in Settings, look at the KB number in the same line and try the update on that PC with the fixes above, starting with Fix 1.

Is 0x80240035 the same as 0x80240031, 0x80240036 or 0x80240037?

No. They sit next to each other in Microsoft's error list, but each one means something else. 0x80240031 is WU_E_INVALID_FILE: a file is in the wrong format. Start with the cache reset in Fix 5. 0x80240036 is WU_E_INVALID_OPERATION: the current state does not allow the operation. A restart often clears it (Fix 1). 0x80240037, also searched as 80240037, is WU_E_NOT_SUPPORTED: the operation is not supported. That often points to an update that does not fit the PC.

Why does the update get stuck at 20 or 30 % before 0x80240035?

At that point the download is done and Windows is applying the package. If the job cannot go on, for example because a restart is still pending, the drive is full or a service hangs, the progress stops and Windows Update later reports that the update was not processed. Wait at least 30 minutes the first time, because large updates can pause and then continue. If nothing moves, restart and follow Fix 1 and Fix 2.

Can 0x80240035 appear when upgrading to Windows 11 24H2 or 25H2?

Yes. In one Microsoft Q&A thread the 24H2 upgrade stopped at 6 to 8 % with 0x80240035, and sometimes with 0xC1900101. It was solved with an in-place repair from the official ISO, with third-party antivirus removed for the time of the upgrade and the internet disconnected. Free up space first (Fix 2), then use Fix 8. The manual install from the Update Catalog in Fix 6 is meant for monthly updates.

Will resetting the Windows Update components delete my files?

No. The reset renames two system folders that hold update downloads and catalog data, SoftwareDistribution and catroot2. Your documents, programs and installed updates are not touched. Windows builds new folders on the next check and downloads the pending updates again. The visible side effect is that the Update history list can look empty afterwards. You can delete the renamed .old folders later to win back space.

Should I turn off my antivirus to fix 0x80240035?

Not for good. Microsoft Defender, the protection built into Windows, does not need to be turned off for updates. A third-party security suite can get in the way of a version upgrade, and in the Q&A case it was removed for the upgrade only. If you try that, pause or remove the suite for one run and turn it back on, or reinstall it, right after the update. Never leave the PC without protection.

Is it safe to leave the update failed?

Not for long. Monthly cumulative updates carry security fixes, and a PC that keeps failing them stays exposed. A newer cumulative update replaces the older one, so you do not need to install every failed update separately, but the next one must go through. If you cannot fix it today, at least restart the PC and free up space so the next monthly update has a fair chance.

Where does Microsoft explain error 0x80240035?

In the Windows Update error code list by component on Microsoft Learn. It gives the name WU_E_UPDATE_NOT_PROCESSED and the one-line description, but no fix. Microsoft Q&A has threads about the code where advisors suggest the troubleshooter, the component reset and an in-place repair. Those are the same steps as on this page, here ordered from the quickest to the biggest.