Temporarily disable third-party antivirus, do a clean boot (disable non-Microsoft startup services), reset the Windows Update cache, and install the update again.

What 0x80070020 means

0x80070020 is ERROR_SHARING_VIOLATION: a file was in use by another process. Real-time scanners and backup or sync software that lock files during updates are common causes.

Signs of the problem

  • Update fails with 0x80070020.
  • Feature upgrade stops partway through.

What causes 0x80070020

  • Antivirus scanning or locking update files.
  • Backup/sync tools holding files.
  • Stuck update services.

Fixes to try, in order

  1. Pause security softwareDisable or uninstall third-party antivirus temporarily.
  2. Clean bootmsconfig → Services → Hide all Microsoft services → Disable all; Startup apps off; restart and update.
  3. Reset update componentsRun the commands below.
  4. Run the troubleshooterWindows 11: Settings → System → Troubleshoot → Other troubleshooters → Windows Update → Run.
  5. Re-enable servicesAfter the update, undo the clean-boot changes in msconfig.

Command

net stop wuauserv
net stop bits
net stop cryptsvc
ren %systemroot%\SoftwareDistribution SoftwareDistribution.old
ren %systemroot%\System32\catroot2 catroot2.old
net start cryptsvc
net start bits
net start wuauserv

Run each line in an elevated Command Prompt. Renaming these folders only clears the update download cache; Windows rebuilds them.

How to tell it worked: The update installs and Update history shows success.

Prevent it from coming back

Keep one antivirus product and pause backup jobs during big updates.