Basics

15 reasons why Security updates don’t work in Windows 10 (and how to fix it)

by Jonathan Dudamel
11 min read

A quick, practical answer: most of the time Security updates don’t work in Windows 10 because a service, file, setting, or resource the update process needs is missing, blocked, or corrupted — and the fixes range from restarting services to repairing system files and clearing update caches. In this article you’ll learn the most common 15 causes for failed security updates and step-by-step fixes you can use right away.

You will see causes like network problems, disabled Windows Update services, corrupt update components, third-party interference, and disk issues — plus commands, menus, and tips to resolve each one.

Contents show

Key Takeaway

Most Windows Update failures are fixable by ensuring network access, freeing disk space, restarting Windows Update services, clearing the SoftwareDistribution cache, and repairing system files with SFC and DISM; do those first, then address third-party software, drivers, and policy blocks if problems persist.

Quick Fix Guide

Quick Fix Guide

Reason for the Problem Quick Solution
1. No or unstable internet connection Reconnect to a stable network, disable VPN/proxy, and retry updates.
2. Incorrect system date and time Set correct date/time or enable Set time automatically.
3. Low disk space Free up at least 10–20 GB or run Disk Cleanup and remove temporary files.
4. Corrupt Windows Update components Stop update services, delete SoftwareDistribution and Catroot2, then restart services.
5. Disabled or stopped update services Start Windows Update, BITS, and Cryptographic Services and set to Automatic.
6. Third-party antivirus/firewall blocking Temporarily disable or uninstall the security software and test updates.
7. Metered connection enabled Turn off Set as metered connection for your network.
8. Pending restart waiting to complete Restart Windows to complete installations and pending actions.
9. Corrupt system files Run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth.
10. Outdated or incompatible drivers Update critical drivers (network, storage) via Device Manager or vendor site.
11. Group Policy or registry blocking updates Revert restrictive Group Policy or registry settings that disable updates.
12. Windows Update agent or buggy update Manually download/install the KB from Microsoft Update Catalog.
13. Insufficient account permissions Use an administrator account or enable the built-in Administrator to run updates.
14. Windows Update stuck installing or downloading Run the Windows Update troubleshooter and reset update components.
15. Disk errors or hardware failure Run chkdsk and check SMART; repair or replace failing disk.

Detailed Fixes for “Security updates don’t work in Windows 10”

1. No or unstable internet connection

Why this causes the problem

  • Windows Update needs a reliable connection to Microsoft servers. Intermittent or blocked connections will fail downloads or throw errors.
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Step-by-step solution

  1. Open Settings > Network & Internet.
  2. Check Status to see if you’re connected; if not, reconnect or troubleshoot using Network troubleshooter.
  3. If using VPN/proxy, temporarily disconnect it: Settings > Network & Internet > Proxy turn off Use a proxy server, or disconnect VPN software.
  4. Open an admin Command Prompt and run:
    • ping www.microsoft.com to check reachability.
    • nslookup windowsupdate.microsoft.com to ensure DNS resolves.
  5. If DNS fails, try setting DNS to Google: Settings > Network > Change adapter options > right-click adapter > Properties > IPv4 > Properties and set DNS to 8.8.8.8 / 8.8.4.4.
    Tip: Wireless hotspots or corporate networks may block update servers — try a home network or tethered mobile hotspot for testing.

2. Incorrect system date and time

Why this causes the problem

  • TLS/HTTPS validation fails if system date/time are wrong; secure connections to update servers will be rejected.

Step-by-step solution

  1. Open Settings > Time & Language > Date & time.
  2. Enable Set time automatically and Set time zone automatically, or manually correct them and click Sync now.
  3. Reboot and retry Windows Update.
    Tip: If syncing fails, check Internet connectivity or try another time server via Control Panel > Date and Time > Internet Time > Change settings.

3. Low disk space

Why this causes the problem

  • Updates require temporary space to download and extract; insufficient free space causes download failures or install errors.

Step-by-step solution

  1. Open Settings > System > Storage to see free space.
  2. Run Disk Cleanup: open Start, type Disk Cleanup, select drive C:, click Clean up system files, check Windows Update Cleanup, Temporary files, and remove them.
  3. Optionally move large files to external storage or uninstall unused apps: Settings > Apps > Apps & features.
  4. Reboot and rerun Windows Update.
    Tip: Keep at least 10–20 GB free before major feature updates.

4. Corrupt Windows Update components (SoftwareDistribution / Catroot2)

Why this causes the problem

  • The update cache or cryptographic container can become corrupt and block new downloads/installs.

Step-by-step solution

  1. Open an elevated Command Prompt (right-click Start > Command Prompt (Admin) or Windows PowerShell (Admin)).
  2. Stop services:
    • net stop wuauserv
    • net stop bits
    • net stop cryptsvc
  3. Rename update folders:
    • ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
    • ren C:\Windows\System32\catroot2 catroot2.old
  4. Restart services:
    • net start wuauserv
    • net start bits
    • net start cryptsvc
  5. Reattempt Windows Update via Settings > Update & Security > Windows Update.
    Note: Renaming preserves data for troubleshooting; after successful updates you can delete the .old folders.

5. Disabled or stopped update services

Why this causes the problem

  • Windows Update, BITS, and Cryptographic Services must run for downloads and installations to work.

Step-by-step solution

  1. Press Windows + R, type services.msc and press Enter.
  2. Find and check these services:
    • Windows Update (wuauserv) — set Startup type: Automatic (Delayed Start).
    • Background Intelligent Transfer Service (BITS) — set Automatic.
    • Cryptographic Services — set Automatic.
  3. Right-click each and choose Start if not running.
  4. Retry updates.
    Tip: If a service won’t start, note the error code and look up details; event viewer may also contain clues.

6. Third-party antivirus/firewall blocking

Why this causes the problem

  • Security software may mistakenly block update downloads or the installers’ actions.

Step-by-step solution

  1. Temporarily disable third-party antivirus/firewall or exit the program from its system tray icon.
  2. If unsure, uninstall the software via Settings > Apps > Apps & features (a reinstall can be done later).
  3. Reboot and try Windows Update again.
  4. If updates succeed, add exceptions or switch to a different security product.
    Note: Do not leave the system unprotected longer than necessary; re-enable Windows Defender (Settings > Update & Security > Windows Security) if disabling third-party protection.
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7. Metered connection enabled

Why this causes the problem

  • Windows may block large updates on metered connections to save data.

Step-by-step solution

  1. Open Settings > Network & Internet > Wi-Fi or Ethernet.
  2. Click your connection name, then toggle Set as metered connection off.
  3. Retry Windows Update.
    Tip: For mobile hotspots, Windows often sets them as metered by default.

8. Pending restart waiting to complete

Why this causes the problem

  • Previous updates, installs, or pending file operations can lock components until a reboot finishes them.

Step-by-step solution

  1. Save work and fully restart the PC: Start > Power > Restart.
  2. After restart, open Settings > Update & Security > Windows Update and check for updates.
  3. If Windows still shows pending operations, run gpupdate /force in an elevated Command Prompt.
    Tip: A shutdown with hold-shift bypasses fast startup; use a full restart to clear locks.

9. Corrupt system files

Why this causes the problem

  • Damaged OS files can prevent the update agent or installers from running.

Step-by-step solution

  1. Open an elevated Command Prompt and run:
    • sfc /scannow
  2. If SFC reports issues it can’t fix, run DISM:
    • DISM /Online /Cleanup-Image /RestoreHealth
  3. Re-run sfc /scannow after DISM completes, then restart and retry Windows Update.
    Note: DISM requires internet access to download healthy files for repairs.

10. Outdated or incompatible drivers

Why this causes the problem

  • Drivers for network, storage, or critical subsystems can prevent downloads or installations.

Step-by-step solution

  1. Open Device Manager (right-click Start).
  2. Inspect key devices (Network adapters, Storage controllers, Display adapters) for warnings.
  3. Right-click a device and choose Update driver > Search automatically.
  4. For network/storage drivers, prefer vendor downloads (Dell/HP/Intel) and install the latest stable drivers.
  5. Reboot and try updates.
    Tip: If a new driver breaks updates, roll back the driver in Device Manager > Properties > Driver > Roll Back Driver.

11. Group Policy or registry blocking updates

Why this causes the problem

  • Enterprise or misconfigured local policies can prevent Windows from downloading or applying updates.

Step-by-step solution

  1. Open gpedit.msc (available on Pro/Enterprise): check Computer Configuration > Administrative Templates > Windows Components > Windows Update for restrictive policies (e.g., Configure Automatic Updates set to Disabled).
  2. Set problematic policies to Not Configured or adjust appropriately.
  3. For Home edition, check registry keys:
    • Run regedit, navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate — delete or modify keys that disable updates.
  4. Run gpupdate /force then restart and check updates.
    Warning: Be careful editing Group Policy and registry; export keys before changes.

12. Windows Update agent or buggy update

Why this causes the problem

  • Sometimes a specific update is buggy, or the Windows Update agent needs updating manually.

Step-by-step solution

  1. Find the KB number in Settings > Update & Security > Windows Update > View update history.
  2. Download the KB manually from https://www.catalog.update.microsoft.com/ and install.
  3. If the update fails, temporarily hide it using the Show or hide updates troubleshooter package from Microsoft and wait for a fixed release.
  4. To update the update agent, install latest cumulative or servicing stack updates manually.
    Tip: Installing servicing stack updates first can fix reliability of subsequent updates.

13. Insufficient account permissions

Why this causes the problem

  • Non-administrator accounts might not have rights to apply certain updates.

Step-by-step solution

  1. Ensure you sign in as an administrator or use an admin account.
  2. To enable the built-in Administrator: open elevated Command Prompt:
    • net user Administrator /active:yes
  3. Sign out, sign into Administrator, and retry updates.
  4. After fixing, disable the built-in Administrator for security:
    • net user Administrator /active:no
      Note: Use built-in Administrator only temporarily; create or use a standard admin account for regular tasks.
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14. Windows Update stuck (download/install stuck)

Why this causes the problem

  • The update process can hang due to resources, cached corruption, or a specific update loop.

Step-by-step solution

  1. Run Settings > Update & Security > Troubleshoot > Additional troubleshooters > Windows Update > Run the troubleshooter.
  2. If stuck at a percentage for a long time, stop updates and clear caches:
    • Stop services (net stop wuauserv, net stop bits).
    • Delete C:\Windows\SoftwareDistribution\Download contents.
    • Start services again.
  3. Reboot, then attempt the update.
    Tip: For in-place upgrade locks, use the Windows 10 Media Creation Tool to upgrade and preserve files — this often completes stuck feature updates.

15. Disk errors or hardware failure

Why this causes the problem

  • Bad sectors or failing drives can prevent files from being written or read during update installs.

Step-by-step solution

  1. Open an elevated Command Prompt and run:
    • chkdsk C: /f /r
    • Reboot when prompted to allow a full scan & repair.
  2. Check SMART status using tools like CrystalDiskInfo or vendor utilities.
  3. If the disk reports failing SMART attributes, back up immediately and replace the drive.
  4. After repairs or disk replacement, reinstall Windows or restore from backup and retry updates.
    Tip: Always maintain backups before disk repair operations.

Additional tools and resources you may need

  • Microsoft Update Catalog — for manual KB downloads: https://www.catalog.update.microsoft.com
  • Windows Update Troubleshooter — Settings > Update & Security > Troubleshoot or download from Microsoft.
  • Windows 10 Media Creation Tool — useful for in-place upgrades and repairs.
  • Windows Defender Offline — to eliminate persistent malware that blocks updates.
  • Event Viewer — check Applications and Services Logs > Microsoft > Windows > WindowsUpdateClient for specific error codes.
  • System Restore / Recovery options — use Settings > Update & Security > Recovery to roll back changes if needed.
  • Support forums and Microsoft Support — for rare or complex error codes.

FAQ

How do I force-install a specific security update?

Download the KB package from the Microsoft Update Catalog and run the appropriate .msu or .cab installer as administrator; reboot after installation.

Can I postpone security updates safely?

Security updates fix vulnerabilities and are not recommended to postpone long-term; if you must delay, enable timely installation later and keep backups — but avoid indefinite postponement.

How can I check detailed Windows Update error codes?

Open Event Viewer > Windows Logs > System and Applications and Services Logs > Microsoft > Windows > WindowsUpdateClient; match the error code to Microsoft documentation or search it online.

Will resetting Windows Update components delete my personal files?

No — resetting SoftwareDistribution and related components only removes cached update files; your personal data remains intact, but always back up important files before major fixes.

What if a security update breaks my system after installing?

Boot into Safe Mode, uninstall the update via Settings > Update & Security > Recovery > Uninstall updates, or use System Restore to revert to a prior point; report the issue to Microsoft if it’s widespread.

Conclusion

Troubleshooting when Security updates don’t work in Windows 10 is usually a process of elimination: check connectivity, free space, services, and system integrity first, then address third-party interference, drivers, policies, or hardware. Following the steps above will resolve most update failures and restore your system’s ability to receive security updates.

About the author

Jonathan Dudamel

Jonathan Dudamel

I'm Jonathan Dudamel, an experienced IT specialist and network engineer passionate about all things Windows. I have deep expertise in Microsoft project management, virtualization (VMware ESXi and Hyper-V), and Microsoft’s hybrid platform. I'm also skilled with Microsoft O365, Azure ADDS, and Windows Server environments from 2003 through 2022.

My strengths include Microsoft network infrastructure, VMware platforms, CMMS, ERP systems, and server administration (2016/2022).

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