How to Turn Off Windows Defender and Antivirus Protection

Why you might disable Windows Defender temporarily

Windows Defender (also called Windows Security or Defender Antivirus) runs automatically on Windows 10 and Windows 11. It scans files, monitors downloads, and blocks suspected threats. Most of the time you should leave it on — it catches real malware and runs in the background without slowing your system much.

You might disable it temporarily for specific reasons: installing software that Defender flags incorrectly, running performance tests that need the CPU free, or troubleshooting whether Defender itself is causing a problem. Disabling it permanently is different — that leaves your system unprotected, and we do not recommend it.

If you have another antivirus program installed (like Norton, McAfee, or Bitdefender), Windows Defender usually turns itself off automatically. If it does not, you can disable it manually to avoid conflicts between two security programs running at once.

Key Takeaways

You can turn off Windows Defender temporarily through Windows Security settings, but it re-enables itself after a restart or after a set time period.
Disabling real-time protection stops active scanning but leaves other Defender features running, so it is safer than a full disable.
If you have another antivirus installed, check whether Defender has already turned itself off before you disable it manually.
Disabling Defender permanently requires Group Policy (Windows Pro and higher) or Registry changes, and leaves your system without built-in protection.

Disable real-time protection in Windows Security

The fastest way to turn off Defender scanning is through the Windows Security app. This disables real-time protection — the feature that watches files as you read and open them — but leaves other Defender features in place. The protection turns back on automatically after you restart your computer or after a few hours, depending on your Windows version.

Open Windows Security by typing "Windows Security" into the Start menu search box and clicking the app. Select Virus & threat protection on the left side. Under "Virus & threat protection settings," click Manage settings. Toggle Real-time protection to the off position. Windows will ask you to confirm — click Yes. You will see a yellow warning icon next to "Virus & threat protection," which means protection is currently off.

This method works on all Windows 10 and Windows 11 versions. The setting does not stick after a restart, so you will need to repeat these steps if you restart your computer and want protection off again.

Check if another antivirus has already disabled Defender

If you installed Norton, McAfee, Bitdefender, Kaspersky, Avast, or another third-party antivirus, Windows Defender should have disabled itself automatically. You can verify this in Windows Security without making any changes.

Open Windows Security and go to Virus & threat protection. Look at the top of the page under "Virus & threat protection." If you see a message like "Your device is being protected by [antivirus name]," then Defender is already off and you do not need to disable it manually. If you see a yellow warning or a message saying protection is off, then Defender did not disable itself, and you can use the steps above to turn it off.

Running two antivirus programs at the same time slows your computer and can cause them to block each other's files. If Defender did not turn off automatically, disable it through Windows Security so only your chosen antivirus runs.

Disable Defender permanently using Group Policy (Windows Pro only)

If you want Defender to stay off even after restart, you need to use Group Policy Editor. This method only works on Windows Pro, Enterprise, or Education editions — Home edition does not include Group Policy.

Press Windows key + R to open the Run dialog. Type gpedit.msc and press Enter. Navigate to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus. Find the setting called Turn off Microsoft Defender Antivirus and double-click it. Select Enabled and click OK. Restart your computer for the change to take effect.

This disables Defender completely, including real-time protection and periodic scans. Your computer will have no built-in antivirus protection, so you should have another security program installed before you make this change. If you change your mind later, return to the same setting, select Not Configured, and restart.

Disable Defender permanently using Registry (all Windows versions)

If you have Windows Home edition and need Defender off permanently, you can edit the Registry. This method is more technical than Group Policy, and mistakes in the Registry can cause Windows problems, so proceed carefully.

Press Windows key + R, type regedit, and press Enter. The Registry Editor will open. Navigate to HKEY_LOCAL_MACHINE > SOFTWARE > Policies > Microsoft > Windows Defender. If the Windows Defender folder does not exist, right-click on "Microsoft," select New > Key, and name it "Windows Defender."

Right-click inside the Windows Defender folder, select New > DWORD (32-bit) Value, and name it DisableAntiSpyware. Double-click the new entry, change the value from 0 to 1, and click OK. Restart your computer. Defender will be disabled after the restart.

To re-enable Defender later, return to the same Registry location, double-click DisableAntiSpyware, change the value back to 0, and restart.

What happens when Defender is off

With real-time protection disabled, Windows stops scanning files as you read them and stops monitoring running programs. You can still manually scan your computer by opening Windows Security, going to Virus & threat protection, and clicking Scan options to choose a quick scan or full scan.

If Defender is completely disabled (through Group Policy or Registry), even manual scans will not work, and Windows will not warn you about suspicious files. Your computer becomes vulnerable to malware, ransomware, and other threats. For this reason, you should have another antivirus program running before you disable Defender permanently.

Windows will display a red X in the system tray (bottom right corner) to remind you that protection is off. Some Windows updates and security patches may re-enable Defender automatically, especially after major Windows updates.

Re-enable Windows Defender

If you disabled real-time protection through Windows Security, it re-enables automatically after a restart or after several hours. To turn it back on when ready, open Windows Security, go to Virus & threat protection > Manage settings, and toggle Real-time protection back on.

If you disabled Defender through Group Policy, open Group Policy Editor again, navigate to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus, find Turn off Microsoft Defender Antivirus, and change it to Not Configured. Restart your computer.

If you disabled Defender through Registry, open Registry Editor, navigate to HKEY_LOCAL_MACHINE > SOFTWARE > Policies > Microsoft > Windows Defender, double-click DisableAntiSpyware, change the value back to 0, and restart.

Frequently Asked Questions

Will disabling Windows Defender speed up my computer?

Real-time protection uses a small amount of CPU and memory, but the difference is usually not noticeable on modern computers. Disabling Defender may free up 1 to 3 percent of your CPU during heavy scanning, but you will lose protection against malware. If your computer feels slow, the cause is usually something else — check your disk usage, RAM, or running programs instead.

Can I disable just Windows Defender and keep other Windows Security features?

Yes. Disabling real-time protection through Windows Security settings turns off scanning but leaves firewall, app control, and other security features running. If you disable Defender completely through Group Policy or Registry, you lose only the antivirus part — Windows Firewall and other tools stay active.

What if Windows Defender keeps turning back on?

Windows automatically re-enables Defender if no other antivirus is detected, or after major Windows updates. If you have another antivirus installed, make sure it is running and up to date. If Defender keeps re-enabling and you want it off, use Group Policy (Pro edition) or Registry changes instead of the Windows Security toggle.

Is it safe to disable Windows Defender if I have another antivirus?

Yes, as long as your other antivirus is running and actively scanning. Two antivirus programs running at the same time cause conflicts and slow your computer. Disable Defender so only one program protects your system. If your other antivirus stops working or you uninstall it, re-enable Defender when ready.

Do I need to disable Windows Defender to install software?

Usually not. If Defender blocks a file you trust, you can add it to the exclusion list instead of disabling protection entirely. Open Windows Security, go to Virus & threat protection > Manage settings > Add exclusions, and select the file or folder. This lets the file through while keeping Defender active for everything else.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.