Windows Security (Microsoft Defender Antivirus) protects your PC in real time, but sometimes it gets in the way. It might block a program you trust, slow down a big file copy or install, or conflict with another security tool. You can turn off real-time protection temporarily in a few clicks. Turning Defender off permanently is harder by design, because Windows turns it back on to keep you protected. This guide explains the safe options in Windows 10 and Windows 11, from a temporary switch to exclusions and replacing Defender with another antivirus.
Quick Answer
Open Windows Security, go to Virus & threat protection > Manage settings (under Virus & threat protection settings), and turn off Real-time protection. Click Yes in the prompt. It turns back on automatically after a short time or when you restart.
Turn Off Real-Time Protection Temporarily
- Click Start, type Windows Security, and open it.
- Click Virus & threat protection.
- Under Virus & threat protection settings, click Manage settings.
- Turn off Real-time protection.
- Click Yes in the User Account Control prompt.
Do what you need to do, then turn it back on, or let Windows turn it on automatically. Scheduled scans still run, and files you already downloaded aren’t scanned until protection is back on.
Better Option: Allow One File or Folder (Exclusions)
If Defender keeps blocking a program you trust, add an exclusion instead of turning protection off:
- In Virus & threat protection > Manage settings, scroll to Exclusions and click Add or remove exclusions.
- Click Add an exclusion and choose File, Folder, File type or Process.
- Select the item and confirm.
Only exclude files from sources you trust completely. To restore something Defender already quarantined, go to Protection history, select the item, and choose Actions > Restore or Allow on device.
Turn Off Defender “Permanently”
The Supported Way: Install Another Antivirus
When you install another antivirus program that registers with Windows, Microsoft Defender Antivirus turns off its real-time protection automatically and the other product takes over. If you uninstall that program, Defender turns back on. This is the only supported way to keep Defender off long-term.
Why Registry and Group Policy Tricks No Longer Work
Older guides tell you to set DisableAntiSpyware in the registry or enable Turn off Microsoft Defender Antivirus in Group Policy. On current versions of Windows 10 and 11, Tamper Protection blocks these changes, and Microsoft has said the DisableAntiSpyware setting is ignored on consumer devices. Turning Tamper Protection off to force it can leave the PC unprotected and may be reversed by updates, so we don’t recommend it.
Can You Delete Windows Defender?
No. Defender is part of Windows and can’t be uninstalled safely. Tools that claim to remove it modify system files, can break Windows Update, and leave the PC without protection.
Other Parts of Windows Security
- Firewall: Firewall & network protection > select a network > turn off Microsoft Defender Firewall. It’s better to allow a specific app through the firewall instead.
- SmartScreen: App & browser control > Reputation-based protection settings. SmartScreen warns about unrecognized downloads and apps.
- Notifications: to stop Windows Security pop-ups without turning protection off, go to Settings (the gear in Windows Security) > Manage notifications.
If You Can’t Turn It Off
- “This setting is managed by your administrator”: a work or school policy controls it. Contact your IT department.
- Options are grayed out: another antivirus may already be active; manage protection in that program instead.
- It turns back on by itself: that’s by design for the temporary switch.
Stay Safe While Protection Is Off
- Don’t browse unfamiliar sites, open email attachments or run downloads while Defender is off.
- Turn real-time protection back on as soon as you’re done.
- Run a quick scan afterward: Virus & threat protection > Quick scan.
Related: Add an exclusion to Windows Defender.
Frequently Asked Questions
Does turning off Windows Security make my PC faster?
Only slightly during heavy file activity. For everyday use, Defender’s impact is small, and exclusions for large project folders are a safer speed-up.
Is Microsoft Defender good enough on its own?
For most home users, yes. It scores well in independent tests and is updated automatically.
How do I turn it back on?
Go back to Virus & threat protection > Manage settings and turn on Real-time protection, or click Turn on on the Windows Security home page.
Summary
- Open Windows Security > Virus & threat protection > Manage settings.
- Turn off Real-time protection temporarily.
- Use exclusions for trusted files instead of leaving protection off.
- Install another antivirus if you want Defender off long-term.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.