Windows Defender stays on by default, but you can disable it temporarily or permanently through Settings, Group Policy, or the Registry — each method works differently depending on your Windows version and whether you have administrator access.

Windows Defender (now called Microsoft Defender) is built into Windows 10 and 11 and runs automatically in the background. Turning it off means your computer loses real-time protection against malware and viruses until you turn it back on or install another antivirus program. Most people disable it only when installing a different antivirus, troubleshooting a conflict, or testing software — not as a permanent solution.

Before you disable it, understand what you are losing: Windows Defender scans files as you download them, monitors running programs, and blocks known threats. Without it or a replacement, your computer is vulnerable. If you are disabling it to run untrusted software, that software may already be malicious.

Key Takeaways

  • The easiest method is to open Settings, go to Privacy & Security, and toggle off Real-time protection — this disables scanning but Windows Defender remains installed.
  • Disabling Windows Defender through Settings is temporary; it may re-enable itself after a Windows update or restart, depending on your Windows version.
  • Permanent disabling requires Group Policy (Windows Pro and Enterprise only) or Registry edits, both of which require administrator access.
  • If you disable Windows Defender, install a different antivirus program immediately — running without any protection leaves your computer exposed to malware.
  • Some software conflicts, driver issues, or malware infections may prevent Windows Defender from being disabled through normal methods.

Disable Windows Defender through Settings (temporary)

This is the fastest method and works on Windows 10 and 11 Home, Pro, and Enterprise editions. Open Settings by pressing Windows key + I, then navigate to Privacy & Security in the left sidebar. Click Windows Security, then Virus & threat protection.

Under "Virus & threat protection settings," click Manage settings. Toggle off Real-time protection. Windows will ask you to confirm; click Yes. Real-time scanning stops immediately, but Windows Defender remains installed on your system.

This method usually lasts until your next restart or Windows update. Some users report Windows Defender re-enabling itself after a few hours or after a restart, especially on Home editions. If you need it off longer, use Group Policy or Registry edits instead.

Disable Windows Defender using Group Policy (permanent on Pro/Enterprise)

Group Policy is available only on Windows Pro, Enterprise, and Education editions — not Home. Press Windows key + R, type gpedit.msc, and press Enter. If you see an error, you have Home edition and must use the Registry method instead.

In the Group Policy Editor window, navigate to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus. Find the policy called Turn off Microsoft Defender Antivirus and double-click it. Select Enabled, then click Apply and OK.

Restart your computer. Windows Defender will remain off after restart and updates, though you can re-enable it by setting the same policy back to Not Configured or Disabled. This method survives Windows updates, unlike the Settings method.

Disable Windows Defender using Registry (permanent on all editions)

This method works on all Windows versions but requires editing the Registry, which can cause problems if done incorrectly. Back up your Registry first: press Windows key + R, type regedit, and press Enter. In the Registry Editor, go to File > Export, choose a location and filename, and click Save.

Navigate to HKEY_LOCAL_MACHINE > SOFTWARE > Policies > Microsoft > Windows Defender. If the Windows Defender folder does not exist, right-click the Windows folder, select New > Key, and name it Windows Defender. Right-click in the empty space on the right, select New > DWORD (32-bit) Value, and name it DisableAntiSpyware. Double-click it, change the value to 1, and click OK.

Restart your computer. Windows Defender will be disabled. To re-enable it, change the DisableAntiSpyware value back to 0 or delete it entirely. This method persists through updates and restarts.

What to do if Windows Defender will not disable

Malware sometimes prevents Windows Defender from being disabled or even from opening. If you cannot access Windows Defender settings or the toggle does not work, restart your computer in Safe Mode with Networking: restart Windows, hold Shift while clicking the power button, select Restart, then choose Troubleshoot > Advanced options > Startup Settings > Safe Mode with Networking.

In Safe Mode, try disabling Windows Defender again through Settings. If it still will not disable, your computer may be infected. Run a full scan with Windows Defender (or another antivirus if you have one installed) before attempting to disable it. If you cannot scan or the problem persists, consider using a bootable antivirus tool like Kaspersky Rescue Disk or Bitdefender Rescue Environment, which run outside Windows and can remove infections that prevent normal tools from working.

Another cause is a conflicting antivirus program that has not been fully uninstalled. If you recently removed antivirus software, use its manufacturer's removal tool (available on their website) to clean up leftover files and Registry entries, then try disabling Windows Defender again.

Install replacement antivirus before disabling Windows Defender

If you are disabling Windows Defender to use a different antivirus, install the replacement first. Download it from the publisher's official website, run the installer, and let it complete. Most antivirus programs will detect Windows Defender and offer to disable it automatically during installation.

If your new antivirus does not disable Windows Defender automatically, disable it yourself using one of the methods above. Do not leave your computer without active antivirus protection — the gap between disabling Windows Defender and activating the replacement is a window for infection.

Some antivirus programs (like Norton, McAfee, or Kaspersky) include their own real-time protection and will conflict with Windows Defender if both are running. Others (like Malwarebytes) are designed to run alongside Windows Defender. Check your antivirus documentation to see whether it is compatible with Windows Defender or requires it to be disabled.

Re-enable Windows Defender when you need it back

If you disabled Windows Defender through Settings, open Settings > Privacy & Security > Windows Security > Virus & threat protection > Manage settings and toggle Real-time protection back on.

If you disabled it through Group Policy, open Group Policy Editor again, navigate to the same policy, set it back to Not Configured, and restart. If you disabled it through Registry, change the DisableAntiSpyware value back to 0 and restart.

After re-enabling, run a full scan to check for any threats that may have entered while protection was off. This can take an hour or more depending on your drive size.

Frequently Asked Questions

Will disabling Windows Defender speed up my computer?

Slightly, but not noticeably for most users. Windows Defender uses minimal CPU and memory on modern computers. If your computer feels slow, the cause is usually something else — too many startup programs, a full hard drive, or malware. Disabling Windows Defender to gain speed is not worth the security risk.

Can I disable Windows Defender on Home edition permanently?

Not through Group Policy, which is not available on Home. You can use Registry edits (the method described above) or disable it through Settings, though Settings disabling may not survive a restart. Registry edits are more reliable on Home edition.

What if I uninstall Windows Defender instead of disabling it?

You cannot fully uninstall Windows Defender — it is part of Windows. You can disable it, but the files remain. Attempting to delete Windows Defender files manually will cause system errors and is not recommended.

Is it safe to disable Windows Defender if I do not have another antivirus?

No. Your computer will have no real-time protection against malware, viruses, or ransomware. Only disable Windows Defender if you are installing a different antivirus program immediately, or if you are troubleshooting a specific conflict and plan to re-enable it quickly.

Why did Windows Defender turn back on after I disabled it?

If you disabled it through Settings, Windows may re-enable it after an update or restart, especially on Home edition. Use Group Policy (Pro/Enterprise) or Registry edits for permanent disabling. If you used those methods and it still re-enabled, check that the setting was saved correctly by opening Group Policy Editor or Registry Editor again and verifying the value.