The quickest way to disable Windows Defender

To turn off Windows Defender temporarily, open the Windows Security app, go to Virus & threat protection, select Manage settings, and toggle off Real-time protection. This stops active scanning but leaves other protections in place. The setting reverts to on when you restart your computer.

If you need Defender off for longer than one restart, you can disable it through Group Policy (on Windows Pro, Enterprise, or Education editions) or the Registry (all editions). Both methods require you to turn it back on manually — it will not re-enable automatically.

Windows Defender is the built-in antivirus that runs by default on all Windows 10 and Windows 11 machines. You might disable it temporarily to install software that triggers false alarms, to test another security program, or to troubleshoot a conflict with another tool.

Key Takeaways

  • Toggling off Real-time protection in Windows Security is the fastest method and automatically re-enables when you restart.
  • Disabling Defender through Group Policy or Registry keeps it off across restarts until you manually turn it back on.
  • Some Windows editions (Home) do not have Group Policy access, so the Registry method works on all versions.
  • Third-party antivirus software often disables Defender automatically, so check your security program settings before manually turning it off.

Disable Defender through Windows Security (temporary, one restart)

This is the simplest method and the one most people use. Open Windows Security by typing "Windows Security" into the search box and pressing Enter. Click Virus & threat protection in the left sidebar.

Under Virus & threat protection settings, click Manage settings. Find the Real-time protection toggle and switch it off. A User Account Control prompt may appear — click Yes to confirm. Real-time protection is now off and Defender will not scan files as you use your computer.

When you restart your computer, Real-time protection turns back on automatically. If you need Defender off for multiple restarts, use the Group Policy or Registry method instead.

Disable Defender through Group Policy (Windows Pro and above)

Group Policy is a Windows management tool available only on Pro, Enterprise, and Education editions. If you have Windows Home, skip to the Registry method.

Press the Windows key and R together to open the Run dialog. Type gpedit.msc and press Enter. Navigate to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus. Double-click Turn off Microsoft Defender Antivirus.

Select Enabled and click OK. Close the Group Policy window. Restart your computer for the change to take effect. Defender will remain off until you return to this same setting and select Disabled or Not Configured.

Disable Defender through Registry (all Windows editions)

The Registry method works on Windows Home, Pro, Enterprise, and Education. Press the Windows key and R together. Type regedit and press Enter. A User Account Control prompt will appear — click Yes.

Navigate to HKEY_LOCAL_MACHINE > SOFTWARE > Policies > Microsoft > Windows Defender. If the Windows Defender folder does not exist, right-click Windows, select New > Key, and name it Windows Defender.

Right-click in the empty space on the right side of the window. Select New > DWORD (32-bit) Value. Name it DisableAntiSpyware and set the value to 1. Close the Registry Editor and restart your computer. Defender will be off after the restart.

To turn Defender back on, return to the same location, find DisableAntiSpyware, and change the value from 1 to 0. Restart again for the change to take effect.

What happens when Defender is off

When you disable Real-time protection, Defender stops scanning files as you download and open them. You lose active protection against malware and viruses until you turn it back on. Windows will show a notification that your device is not protected.

Other Windows security features remain active even when Defender is off — Windows Firewall continues to run, and Windows Update still delivers patches. If you have a third-party antivirus installed, it may activate automatically when Defender turns off.

Disabling Defender does not affect Windows Defender Offline, a separate tool that runs from a bootable USB drive to remove stubborn infections. It also does not disable Windows Defender Application Guard, which isolates Microsoft Edge browsing in a sandbox.

When third-party antivirus turns off Defender automatically

Most commercial antivirus programs — Norton, McAfee, Kaspersky, Bitdefender, and others — automatically disable Windows Defender when they install. They do this to prevent conflicts between two active antivirus engines running at the same time.

If you install a third-party antivirus and then uninstall it, Defender does not always turn back on by itself. Open Windows Security and check the status of Real-time protection. If it is off, toggle it back on manually.

Some antivirus programs include an option to leave Defender enabled as a secondary scanner. Check your antivirus settings before manually disabling Defender — you may not need to.

Reasons to disable Defender temporarily

Software installers sometimes trigger Defender alerts for legitimate programs that use techniques Defender flags as suspicious. If you trust the source and want to install anyway, disabling Defender during installation can prevent the block. Turn it back on immediately after the installation finishes.

Testing a different antivirus product requires Defender off so the two programs do not conflict. Disable Defender, install the test version, run it for as long as you need, then uninstall it and re-enable Defender.

Troubleshooting a system problem sometimes requires isolating whether Defender is the cause. Disable it, reproduce the problem, and see if the issue goes away. If it does, Defender or its settings are likely involved. If the problem persists, Defender is not the cause.

Frequently Asked Questions

Does disabling Windows Defender leave my computer unprotected?

Yes — when Defender is off, you lose active scanning of files and downloads. Windows Firewall remains on, but you have no antivirus protection until you turn Defender back on or install a third-party antivirus. Avoid downloading files or visiting untrusted websites while Defender is disabled.

Will my computer automatically turn Defender back on?

Only if you use the Windows Security toggle method — it re-enables automatically on restart. If you disable Defender through Group Policy or Registry, it stays off until you manually change the setting back. You must restart your computer for either change to take effect.

Can I disable just one part of Defender instead of all of it?

Yes. In Windows Security under Virus & threat protection settings, you can toggle off Real-time protection, Cloud-delivered protection, or Automatic sample submission individually. This lets you disable specific features while keeping others active.

What if I cannot find the Windows Defender folder in the Registry?

Create it manually. Right-click the Windows folder in the Registry path, select New > Key, and name it Windows Defender. Then create the DisableAntiSpyware value inside it as described in the Registry section.

Does disabling Defender affect Windows Update?

No. Windows Update runs independently and continues to deliver security patches even when Defender is off. Disabling Defender only stops the antivirus scanning engine, not system updates or other security features.