How to Turn Microsoft Defender Off or On in Windows 10 and 11 (and Why It Turns Back On)

To temporarily turn off Microsoft Defender Antivirus in Windows 10 or Windows 11, open Windows Security > Virus & threat protection > Manage settings and switch Real-time protection to Off. Windows turns it back on automatically after a short time or at the next restart. To turn it back on yourself, flip the same switch to On. If you only need Defender to stop interfering with one file or folder, add an exclusion instead; it is far safer than switching protection off.

Before you start: understand the risk

While real-time protection is off, files you open, download or run are not scanned. If you have no other antivirus installed, your PC is exposed to malware the entire time. Microsoft explicitly warns against leaving it disabled. Only turn it off for a specific, short task, disconnect from untrusted networks if you can, and turn it back on as soon as you are done.

Common legitimate reasons include troubleshooting a false positive that blocks a known-safe program, or a performance-sensitive task like a large file copy. Turning off antivirus to run cracked software or “activators” is a classic way to get infected; do not do it.

Windows 10 vs Windows 11: what is different

The steps are almost identical because both use the Windows Security app. The main differences are where you find the app and some newer features in Windows 11.

On either version you can also search the Start menu for Windows Security to open it directly.

How to turn off Microsoft Defender real-time protection

1. Click Start, type Windows Security, and open the app.
2. Select Virus & threat protection.
3. Under Virus & threat protection settings, click Manage settings.
4. Switch Real-time protection to Off.
5. Click Yes on the User Account Control prompt. You need an administrator account.

Windows Security will show a warning that your device may be vulnerable. That is expected. Microsoft’s own instructions are on support.microsoft.com.

Other switches on the same page

• Cloud-delivered protection: sends information about suspicious files to Microsoft for faster detection.
• Automatic sample submission: uploads suspicious files for analysis.
• Tamper Protection: prevents apps, scripts and settings changes from disabling Defender behind your back.

For a short troubleshooting step, turning off real-time protection alone is normally enough. Leave the others on.

How to turn Microsoft Defender back on

1. Open Windows Security > Virus & threat protection > Manage settings.
2. Switch Real-time protection to On.
3. Scroll down and confirm Tamper Protection is On.
4. Go back to Virus & threat protection and click Check for updates under protection updates, then run a Quick scan.

Why Defender keeps turning itself back on

This is by design. When you switch off real-time protection with no other antivirus installed, Windows re-enables it automatically after a short period and at the next restart. Microsoft does not publish an exact timer, so do not count on any particular window.

Tamper Protection also plays a part. With it on, changes made by scripts, the registry or Group Policy to disable Defender are blocked or reverted. Microsoft has also retired older registry tricks that used to switch Defender off permanently on consumer PCs. If you are on a work or school computer, these settings may be greyed out because your organization manages them; ask your IT department.

The safer alternative: add an exclusion

If Defender keeps quarantining a program or folder you trust, such as a development project or a game mod folder you created yourself, exclude just that item:

1. Open Windows Security > Virus & threat protection > Manage settings.
2. Scroll to Exclusions and click Add or remove exclusions.
3. Click Add an exclusion and choose File, Folder, File type or Process.
4. Select the item. Defender will skip it while protecting everything else.

Keep exclusions narrow (one folder, not a whole drive) and remove them when you no longer need them. Malware sometimes hides in excluded locations precisely because they are not scanned.

If a file you trust is being flagged, you can also report it to Microsoft as a false positive through Microsoft’s security intelligence submission site.

What about installing another antivirus?

If you install a third-party antivirus that registers with Windows Security, Microsoft Defender Antivirus steps aside automatically and stops real-time scanning so the two do not conflict. If you later uninstall that product, Defender turns back on by itself. You do not need to disable Defender manually before installing another reputable antivirus.

You can check which product is active in Windows Security > Virus & threat protection, where it lists the current antivirus provider.

Bottom line

Turning off Defender’s real-time protection takes a few clicks in Windows Security > Virus & threat protection > Manage settings, and Windows will switch it back on soon after, which is a safety feature, not a bug. For most problems, an exclusion for a single trusted file or folder is the better fix. If you do turn protection off, keep it brief, avoid downloading or opening anything unfamiliar, and make sure both real-time protection and Tamper Protection are back on afterward.

FAQ

Can I permanently disable Microsoft Defender?

On home PCs, not through the normal settings, and it is not recommended. The supported way to replace it is to install another reputable antivirus, which makes Defender step aside automatically.

Why is the Real-time protection switch greyed out?

Your device is likely managed by an organization, or another antivirus product is active. On a work or school PC, contact your IT department.

Does turning off real-time protection also turn off the firewall?

No. The firewall is a separate feature under Windows Security > Firewall & network protection, and it should stay on.

Does Defender still protect Windows 10 after end of support?

Microsoft has said it will keep providing Defender security intelligence updates on Windows 10 for a limited time, but without Windows security patches the system itself grows more vulnerable. Upgrading to Windows 11, if your hardware allows, is the safer path.