How to fix Windows update error 0x800f0989?

Install error 0x800f0989 means Windows could not find the reverse delta of a system file it needs to step back to before it applies the new update, so the update is rolled back. Restart and try once more, then install the failing update by hand. If the same code returns, a repair reinstall that keeps your apps and files is the fix Microsoft points to.

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

What Windows Update error 0x800f0989 means

0x800f0989 comes from the Windows servicing stack, the part of Windows that installs updates. Microsoft lists it as 0x800F0989, PSFX_E_REVERSE_DELTA_MISSING, "seen during cumulative update failures". The download has already finished, so your internet connection is not the cause.

To understand the name, you need to know how a monthly update is built. It does not carry whole files. For each changed file it carries a forward delta from the base version (the version Windows was released with) and a reverse delta back to that base. Your PC keeps the reverse deltas of the version it runs now, so the next update can use them.

Microsoft writes that these files sit in the component store, C:\Windows\WinSxS, with forward deltas under an f folder and reverse deltas under an r folder. When the r file for a component is missing, Windows cannot get back to the base file, the install fails with 0x800f0989, and everything is undone.

Why Windows Update error 0x800f0989 appears

Microsoft gives one cause for the whole group of these servicing errors: the servicing stack is damaged by missing files, an invalid configuration or broken metadata. For 0x800f0989 the missing piece is a reverse delta. How it went missing differs from PC to PC, and the table ties each case to the fix to start with.

Where CBS.log is and what to look for

You do not need the log for Fix 1 or Fix 2. Read it when the update fails a second time: it names the component whose reverse delta is missing. Microsoft points to three files for this group of errors, all in C:\Windows\Logs\CBS: CBS.log, CbsPersist_*.log and CbsPersist_*.cab.

1. Press Win + R, type %windir%\Logs\CBS and press Enter.
2. Copy CBS.log to the Desktop and open the copy in Notepad, so the original stays untouched.
3. Press Ctrl + F and search for 0x800f0989, then for -2146498167. Note the time of the last hit.
4. Look at the lines just above that time. They usually name a component, its version and the folder Windows tried to read.
5. If the attempt was days ago and CBS.log does not hold it, open the newest CbsPersist_ file in the same folder. A .cab file opens like a folder in File Explorer.

Write down the component name and the KB number. One component means a small, local fault, and Fix 2 or Fix 3 has a fair chance. Many components, or the same code after DISM, means the store needs the repair reinstall in Fix 5.

How to fix Windows update error 0x800f0989

Fix 1 and Fix 2 cost little and clear the cases where the store is only half way between two versions. Fix 3 and Fix 4 repair the component store and the update cache. Fix 5 reinstalls Windows over itself and keeps your apps and files: for this code Microsoft says it might be the only resolution, so do not spend a whole day on the earlier fixes.

Fix 1. Restart the PC and retry the update once

5 to 15 minutesNo riskAlways first, above all when the PC has not been restarted since the last update or Windows Update asks for a restart.

Reverse deltas are written when an update finishes. If an earlier install is still pending, the files for the version Windows thinks it runs may not be in place yet. A real restart lets the pending work finish before the next try.

1. Save your work and select Start > Power > Restart. Use Restart, not Shut down, because Fast Startup can skip pending work on shut down.
2. On Windows 11 open Settings > Windows Update. On Windows 10 open Settings > Update & Security > Windows Update.
3. If Windows asks for another restart, restart again before you go on.
4. Select Check for updates. If a newer cumulative update is offered, install that one, because it replaces the failed one.
5. If the failed update is still listed, select Retry next to it once.
6. Open Update history and check whether the update now reads Successfully installed.

Fix 2. Install the failing update by hand from the Microsoft Update Catalog

20 to 40 minutesLow riskOne KB keeps failing in Windows Update while other updates install.

The catalog has the full standalone package of the update, the same one administrators deploy. Answers on Microsoft Q&A and users on forums report that it sometimes installs when Windows Update does not. If it fails with the same code, you know the missing file is on your PC and not in the download.

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

Some newer Windows 11 updates come as more than one MSU file. The KB page then lists them in the order to install. Put all files in one folder, for example C:\packages, and let DISM install them, from Command Prompt opened as administrator:

DISM /Online /Add-Package /PackagePath:C:\packages\<file name of the KB>.msu

Fix 3. Repair the component store with DISM and SFC

20 to 40 minutesNo riskFix 2 failed with the same code, or SFC reports damaged files.

DISM with RestoreHealth checks the WinSxS component store against clean copies and replaces what is damaged, and SFC then repairs the system files that depend on it. It is worth one run because damage rarely stops at one file. We could not confirm on a Microsoft page that it restores missing reverse deltas, so do not repeat it if the update still fails.

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 DISM cannot fetch clean files through a broken Windows Update, give it an ISO of the same Windows version and edition. Right-click the ISO, select Mount, note the drive letter and run:

dism /Get-WimInfo /WimFile:D:\sources\install.wim
DISM /Online /Cleanup-Image /RestoreHealth /Source:wim:D:\sources\install.wim:1 /LimitAccess

Replace D: with your drive letter and the last 1 with the index of your edition from the first command. If the folder holds install.esd, use that name and write esd: in place of wim:.

Fix 4. Reset the Windows Update components

10 minutesLow riskThe update fails at once, at the same percentage, on every try.

Windows reuses what it downloaded into the SoftwareDistribution folder at every retry. Renaming the folder and catroot2 makes it download the update again from zero. This clears a damaged download only. It does not bring back a missing reverse delta, which is why it comes this late.

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 5. Reinstall Windows over itself and keep apps and files

1 to 2 hoursLow riskEvery fix above ended with 0x800f0989, or the code returns with each month's update.

For 0x800F0989 Microsoft writes that an in-place upgrade "might be the only resolution". It "reinstalls the OS while preserving your data, apps, and settings", which builds a new component store with every file and its reverse delta in place, so the next updates have what they need.

On Windows 11 the built-in way is Fix problems using Windows Update:

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.

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

• With installation media: run Microsoft's Media Creation Tool or mount the ISO, run setup.exe, select Upgrade this PC now and check that Keep personal files and apps is listed before you select Install.
• Windows 10 22H2: the same Media Creation Tool route works. Windows 10 left support on 14 October 2025, so this is also a good moment to plan the move to Windows 11.
• Keep the PC online until the reinstall ends, so it finishes with the newest updates.

If error 0x800f0989 is still there

If even the repair reinstall did not clear the code, what comes next depends on who manages the PC. A home PC can use Reset this PC with Keep my files. A work PC or a server needs the logs and the administrator.

• What to send to support: the exact code, the KB number, the OS build from winver and the time of the last failed attempt.
• The lines from CBS.log that name the component.
• Which fixes you already ran, and the last line DISM printed.

How to keep error 0x800f0989 from coming back

Frequently asked questions

What does install error 0x800f0989 mean?

It means Windows Update downloaded an update but could not install it, because a reverse delta file was missing. Microsoft's name for the code is PSFX_E_REVERSE_DELTA_MISSING. Windows rebuilds each changed file by stepping back from your current version to the base version with a reverse delta, then forward to the new version. Without the reverse delta it cannot take the first step, so it rolls the whole update back. Your internet connection is not the cause.

Should I just wait for Microsoft to fix 0x800f0989?

No. This code is not tied to one faulty update that Microsoft can withdraw or replace. The missing file is on your PC, so next month's cumulative update usually fails with the same code. Restart and retry once, then try the manual install from the catalog. If both fail, go to the repair reinstall: Microsoft lists 0x800F0989 among the errors where an in-place upgrade might be the only resolution. Waiting only leaves the PC without security fixes for longer.

How do I fix 0x800f0989 on Windows 11?

Restart, then retry the update in Settings > Windows Update (Fix 1). If it fails, note the KB number in Update history and install it from the Microsoft Update Catalog (Fix 2). If the catalog package fails too, run DISM RestoreHealth and SFC once (Fix 3). When the code still returns, use Fix problems using Windows Update in Settings > System > Recovery, which reinstalls Windows 11 over itself and keeps your apps and files.

How do I fix 0x800f0989 on Windows 10?

The steps are the same as on Windows 11, with the Windows 10 menu names: Settings > Update & Security > Windows Update for the retry, the Microsoft Update Catalog for the manual install, DISM and SFC for the repair. For the repair reinstall, use Microsoft's Media Creation Tool and choose Upgrade this PC now. Windows 10 left support on 14 October 2025, so a PC that cannot update should move to Windows 11 if its hardware allows.

What is 0x800f0989 (-2146498167)?

It is the same error written in two ways. 0x800f0989 is the hexadecimal form, and -2146498167 is the same 32-bit value read as a signed decimal number. Configuration Manager, WSUS reports, PowerShell and some scripts show the decimal form, while Windows Update shows the hexadecimal one. When you search CBS.log, search for both. Every fix on this page applies, whichever form you see.

What is Yükleme hatası - 0x800f0989 or Installationsfehler 0x800f0989?

They are the same message on a Turkish and a German Windows. Yükleme hatası and Installationsfehler both mean install error, and the code after them is the same, so the fixes on this page are the same too. The menu names here are the English ones: on a translated Windows, open Settings, then Windows Update, and follow the same positions. Questions in other languages that land on this page, such as how to solve it or why it happens, are answered by the short answer at the top.

Is 0x800f0989 the same as 0x800f0988 or 0x800f0982?

No, but they are close relatives. All three belong to the same group of servicing errors that Microsoft lists together. 0x800F0982 means a matching component was not found, 0x800F0988 means an invalid delta combination, and 0x800F0989 means the reverse delta is missing. The quick fixes overlap, and for all of them the in-place upgrade is the reliable answer when the quick fixes do not work.

Does the Windows Update troubleshooter fix 0x800f0989?

Rarely. The troubleshooter checks the update services and clears stuck downloads. 0x800f0989 happens after the download, when Windows looks for a reverse delta in the component store, and the troubleshooter does not touch that store. Run it only if you want to rule out the simple cases first: Run the Windows Update troubleshooter. Then return to Fix 1.

Will I lose files if I fix 0x800f0989?

No fix on this page deletes your files. Fix 1 to Fix 4 only touch updates, system components and the update cache. Fix 5 reinstalls Windows but keeps your apps, files and settings, as long as Keep personal files and apps is selected. Back up the files you cannot lose before Fix 5 anyway, because any reinstall can be interrupted. Only Reset this PC, in the section after the fixes, removes installed apps.

Should I turn off my antivirus to install the update?

No, not as a fix. An antivirus does not remove reverse delta files from the component store, and Microsoft does not link this code to security software. If you still want to rule it out, pause protection for one try only and turn it back on right after: Turn off Microsoft Defender protection for a moment. Microsoft Defender never needs to be removed for an update to install.