Windows updates aren't working - what do I do?

Installing updates regularly on your Windows PC is essential if you want to stay protected against malware and take advantages of any new features and functionality. 

At Which? Tech Support, we've heard from many members experiencing issues related to downloading or installing Windows software. This can be a real pain – particularly when you consider that new updates are used to patch security vulnerabilities.

Here, we run through the various ways you can solve the problem.

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Question of the month: How do I fix 'Windows Update failed to install'?

'I've noticed that my Windows 10 computer hasn't been installing updates and I'm still on version 21H1. The updates won't even download and I'm concerned about the security of my system. Can this be fixed?'

Which? Tech Support member

9 ways to fix broken Windows updates

1. Try the Windows Update Troubleshooter

Windows comes with a built-in troubleshooter designed to fix update-related problems. For the most part, this can be enough to fix the vast majority of issues.

• On Windows 10: Select Start > Settings > Update & Security > Troubleshoot > Additional troubleshooters. Next, under 'Get Up and Running', select Windows Update > Run the troubleshooter.
• On Windows 11: Select Start > Settings > System > Troubleshoot  > Other troubleshooters. Next, under 'Most Frequent', select Windows Update > Run.

2. Free up disk space

A lack of disk space can cause Windows updates to fail, so make sure you have plenty of room on your system drive – at least 12 GB.

You can use the built-in Disk cleanup tool to remove unnecessary files. To open it up, select the Start menu and search for Disk Clean-up.

3. Use the Windows Update Assistant

If you're running Windows 10, you can use Update Assistant from Microsoft. This tool is designed to help you stay on top of software upgrades. 

After downloading Update Assistant, updates will be applied to your machine automatically – so you won't need to dig into your system settings and check every couple of weeks for new releases.

Use this direct link to download the Windows Update Assistant to your PC. 

The .exe file will be in your Downloads folder (if you're not sure where this is, open up your yellow File Explorer folder and find it from there). Double-click the file to run it, then follow the onscreen instructions.

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4. Manually download and install available updates

If automatic updates fail, you can instead manually download and install updates from the Microsoft Update Catalog.

Open the Catalog, search for the required update and download it. Then, head to your Downloads folder and double-click the update to install it.

5. Reset Windows Update Components

You can reset Windows Update components to their default settings using Command Prompt.

To start, you'll need to open Command Prompt as an administrator – select the Start menu, type in CMD, right-click on Command Prompt and choose Run as administrator from the context menu.

Run the following commands in order by typing them in and pressing Enter:

• net stop wuauserv – this stops the Windows Update service.
• net stop cryptSvc – this stops Cryptographic Services.
• net stop bits – this stops the Background Intelligent Transfer Service (BITS).
• net stop msiserver – this stops the Windows Installer service.
• ren C:\Windows\SoftwareDistribution SoftwareDistribution.old – this renames the SoftwareDistribution folder, where Windows stores updates that have been downloaded but not yet installed. This helps clear any cache and resolves issues related to file corruption.
• ren C:\Windows\System32\catroot2 catroot2.old – this renames the catroot2 folder, which is used for maintaining catalog files for digitally signed files. It can become corrupted and renaming the folder forces Windows to create a fresh one.
• net start wuauserv – Starts the Windows Update service.
• net start cryptSvc – Starts Cryptographic Services.
• net start bits – Starts BITS.
• net start msiserver – Starts the Windows Installer service.

6. Clear Windows Update Cache

A corrupted Windows Update cache can lead to installation issues, so we suggest clearing it entirely.

Navigate to the SoftwareDistribution folder (C:\Windows\SoftwareDistribution) and delete its contents. When the process is complete, restart your computer.

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7. Run System File Checker (SFC)

The System File Checker (SFC) tool on Windows can scan and repair corrupted system files that might be causing update failures.

Open Command Prompt as an administrator and run the following command: sfc /scannow.

8. Try the DISM command-line tool

The Deployment Image Service and Management tool (DISM) is another powerful tool to fix Windows corruption errors.

Run the following commands in Command Prompt as an administrator:

• DISM /online /cleanup-image /scanhealth
• DISM /online /cleanup-image /restorehealth

9. Reinstall Windows

On Windows 10, run through the following steps:

1. Download the Windows 10 Media Creation Tool
2. Run the tool and accept the terms and conditions
3. Select Upgrade this PC now on the What do you want to do page
4. Allow the tool to download updates and check your PC
5. Choose Keep personal files and apps and select Next

Windows will reinstall and, after rebooting, you should be back at your desktop with updates installed.

Alternatively, if you're using Windows 11, try this:

1. Download a Windows 11 ISO file from Microsoft
2. Right-click the ISO file and choose Mount
3. Run the setup.exe file to start Windows 11 Setup
4. Click Next on the Install Windows 11 page
5. Accept the terms and conditions
6. Ensure Keep personal files and apps is selected and choose Install

Windows will start the reinstall. After you restart your computer, you should be back at your desktop with updates installed.

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