MediumAbout 25 minutesWindows

Windows Update fails or sticks at the same percent

Why will Windows Update not install and keeps showing an error?

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Written by The CommonFixes team · fact checked by CommonFixes review desk

Last updated

Short answer

Update files download into a folder called SoftwareDistribution. If one file is damaged, Windows keeps retrying the same broken copy. Microsoft's troubleshooter and a reset of that folder clear it. The quickest thing to try first: run the built-in troubleshooter — Settings, System, Troubleshoot, Other troubleshooters, then Run next to Windows Update. Let it finish and restart. Most stuck updates end here. Most people are done in about 25 minutes.

Full walkthrough below: 6 steps for Windows, rated medium.

Sounds like this

  • The same error code every time
  • Stuck at a percentage for hours
  • Installs then rolls back on restart

Why it happens

Update files download into a folder called SoftwareDistribution. If one file is damaged, Windows keeps retrying the same broken copy. Microsoft's troubleshooter and a reset of that folder clear it.

Work through these in order

0% done
  1. 1

    Run the built-in troubleshooter

    Settings, System, Troubleshoot, Other troubleshooters, then Run next to Windows Update. Let it finish and restart. Most stuck updates end here.

  2. 2

    Free up disk space

    Updates need several gigabytes. Settings, System, Storage, then use Cleanup recommendations to remove temporary and old delivery files.

  3. 3

    Unplug extra devices and retry

    External drives, phones and printers can stall setup. Leave only keyboard, mouse and charger connected, then check for updates again.

  4. 4

    Reset the update files

    Right click Start, open Terminal as administrator and run these one at a time: net stop wuauserv, net stop bits, ren C:\Windows\SoftwareDistribution SoftwareDistribution.old, net start wuauserv, net start bits. Then check for updates.

  5. 5

    Repair Windows system files

    In the same admin Terminal run DISM /Online /Cleanup-Image /RestoreHealth, then sfc /scannow. Restart when both finish.

  6. 6

    Install the update manually

    Note the KB number in the error, search it on the Microsoft Update Catalog at catalog.update.microsoft.com, download the version matching your Windows, and run it.

If none of that worked

For a feature update that keeps failing, use the Windows 11 Installation Assistant from Microsoft's official download page. It reinstalls Windows over itself and keeps your files and apps.

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Who wrote this and how we checked it

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The CommonFixes team

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CommonFixes review desk

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This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.

A gentle reminder: back up anything you cannot afford to lose before major repairs. If a step ever feels risky, stop and ask a technician. There is no shame in that.