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How to Solve Microsoft Defender Not Updating Problems? Fix This Critical Issue Easily

Microsoft Defender protects Windows computers from viruses and threats. It updates itself in two main ways:

  • Windows Update: Defender gets new files and definitions through regular Windows updates.
  • Direct Defender Updates: Even if Windows Update is off, Defender can still update itself by connecting to Microsoft’s servers.

You can check when Defender last updated by running this command in PowerShell:

Get-MpComputerStatus | Select-Object AntivirusSignatureLastUpdated, AntivirusSignatureVersion | fl

If Defender isn’t updating, you might see errors like “Protection definition update failed (800704C6).” Here’s how to fix it step by step.

Solution 1: Check Internet and Update Settings

Make sure your computer is connected to the internet.

Check for update errors (like 80072f8f or 0x80072ee2). These often mean a network problem or a Windows Update policy block.

Open Windows Update settings and look for “Security Intelligence Update for Microsoft Defender Antivirus — KB2267602.” If it’s missing or stuck, you may need to reset Windows Update.

Solution 2: Confirm Automatic Updates Are On

  1. Open Windows Security (type ms-settings:windowsdefender in the Start menu).
  2. Go to “Virus & Threat Protection Updates.” You’ll see the current version and last update time.
  3. Run this PowerShell command to check update schedules:
    Get-MpPreference | Select-Object SignatureScheduleDay, SignatureScheduleTime

Solution 3: Ensure Defender Services Are Running

Open PowerShell and run:

get-service WdNisSvc, WinDefend, wscsvc | select name, status, starttype

All services should show as “Running.”

Solution 4: Try a Manual Update

  1. Open Command Prompt as Administrator.
  2. Run:
    "%ProgramFiles%\Windows Defender\MpCmdRun.exe" -SignatureUpdate
  3. If you see errors, check the log at %userprofile%\AppData\Local\Temp\MpCmdRun.log.

Solution 5: Fix Network or Proxy Issues

If you get error 0x8024401B, your computer might not reach Microsoft’s servers.

Test the connection:

tnc fe2cr.update.microsoft.com -port 443

Check proxy settings:

netsh winhttp show proxy

If the proxy is wrong, reset it:

netsh winhttp reset proxy

Solution 6: Reset Defender’s Database

If updates still fail, the database may be corrupted.

Reset with:

"%ProgramFiles%\Windows Defender\MpCmdRun.exe" -removedefinitions -all

Update again:

Update-MpSignature -Verbose

If you see “Access Denied” (0x80070005), turn off Tamper Protection in Windows Security first.

Solution 7: Check Group Policy

Run rsop.msc to see if Group Policy is blocking Defender updates.

Look under Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus.

Remove or adjust any settings that might block updates.

Solution 8: Review Event Logs

  1. Open Event Viewer.
  2. Go to Applications and Services Logs > Microsoft > Windows > Windows Defender > Operational.
  3. Look for Event ID 2002 for successful updates or other errors.

Solution 9: Install Updates Manually

  1. Download the latest update file (mpam-fe.exe) from Microsoft’s official site.
  2. Reset Defender:
    cd %ProgramFiles%\Windows Defender
    MpCmdRun.exe -removedefinitions -all
  3. Run the downloaded file as Administrator.

Final Check

Confirm everything is up to date:

Get-MpComputerStatus | Select-Object AntivirusSignatureLastUpdated, AntivirusSignatureVersion

Tips for Smooth Defender Updates

  • Restart your computer after updates.
  • Keep Windows up to date.
  • Avoid third-party antivirus conflicts.
  • Check settings regularly, especially after big Windows updates.

Microsoft Defender protects best when it’s up to date. Follow these steps to keep your computer safe and secure. If problems continue, consider seeking help from a trusted IT professional.