Windows Update Error 0x80070020 — Fix Guide

What Does This Error Mean?

Windows Update error 0x80070020 means a file that needs to be updated is currently locked by another program. It is like trying to edit a document someone else has open. Antivirus software, backup programs, or other security tools are common causes.

Affected Models

Windows 10
Windows 11
Windows 8.1

Common Causes

Antivirus or security software has locked a system file that Windows Update needs to replace
A backup program is accessing system files during the update process
Another Windows Update process is already running in the background
A running service has a file open that the update needs to overwrite
Windows Defender or a third-party security tool is scanning files mid-update

How to Fix It

Restart your PC and try Windows Update again immediately after startup, before other programs fully load.

A fresh restart clears most file locks. Running Windows Update right away, before antivirus scans kick in, often resolves this error.
Temporarily disable your antivirus software. Right-click the antivirus icon in the system tray (bottom-right corner) and choose to disable it for 15–30 minutes. Then run Windows Update.

Re-enable your antivirus immediately after the update finishes. Antivirus software is the most common cause of 0x80070020.
Disable any backup programs (like Acronis, Backup and Sync, or similar) temporarily. These programs lock files as they back them up, which can block updates.

Schedule backups to run at a different time than Windows Update — for example, have backups run at night and updates in the morning.
Make sure only one Windows Update process is running. Open Task Manager, go to the Processes tab, and check that there are not multiple instances of 'Windows Update' or 'TiWorker.exe' running.

TiWorker.exe is the Windows Update worker process. Multiple instances can conflict with each other. If you see duplicates, restart your PC.
Run the Windows Update Troubleshooter. Go to Settings > System > Troubleshoot > Other Troubleshooters > Windows Update > Run. It can detect and release stuck file locks.

The troubleshooter is specifically designed for update errors. It often resolves this error without requiring manual steps.

When to Call a Professional

This error is almost always fixable without professional help. If none of the steps below work, a technician can identify exactly which process has the file locked using Process Explorer. This is a free Microsoft tool but can be tricky to interpret.

Frequently Asked Questions

Which antivirus programs cause this most often?

Almost any real-time antivirus can cause this error. Products like Avast, Bitdefender, Kaspersky, McAfee, and Norton are commonly reported. This is not a flaw in those products — their real-time file protection is just doing its job. Temporarily disabling them during updates is the standard workaround.

Can I see which program has the file locked?

Yes, using Microsoft's free Process Explorer tool. Download it from the Microsoft Sysinternals website. In Process Explorer, go to Find > Find Handle or DLL and search for the file name shown in the update error. It will tell you exactly which program has it locked.

Does this error mean my files will be corrupted?

No. Windows Update stops gracefully when it encounters a locked file — it does not partially overwrite it. Your files are safe. The update simply did not complete and will try again next time.