Turn On Windows Ransomware Protection (Controlled Folder Access) and Allow Apps When Saving Fails

Ransomware is malware that secretly encrypts the photos and documents on your PC and then demands money to unlock them. Windows has a built-in Ransomware protection (Controlled folder access) feature that stops unknown programs from changing your important folders, but it is off by default.

How does it protect you?

• When it's on, only trusted programs can change files in protected folders such as Documents, Pictures, Videos, Music and Desktop.
• If an unfamiliar program tries to change or delete files there, Windows blocks it and shows an "Unauthorized changes blocked" notification.
• It works when Microsoft Defender is your PC's active antivirus. If you use another antivirus, check that product's ransomware protection instead.

Step 1: Turn it on

• Open Windows Security from the Start menu.
• Go to Virus & threat protection → near the bottom, under Ransomware protection, click Manage ransomware protection.
• Switch Controlled folder access to On.
• Under Protected folders, check the default list. You can also add work folders on other drives with Add a protected folder.

Step 2: Allow an app when saving fails

• After turning it on, a program you normally use, such as a photo editor or recording program, may fail to save into Documents or Videos. If you trust the program, add it to the allowed list.
• On the same Manage ransomware protection page, click Allow an app through Controlled folder access → Add an allowed app.
• Choose Recently blocked apps to see the program that was just blocked and add it right away. If it isn't listed, use Browse all apps and pick the program's .exe file.
• Don't allow programs you don't recognize or that came from an unknown source. Blocking those is the whole point of this feature.

For extra safety

• Backup is the best defense. Ransomware protection can't guarantee 100% protection, so keep copies of important files on an external drive or in the cloud.
• If you use OneDrive, you can set up Ransomware data recovery on the same Windows Security page.
• Keep Windows and your antivirus up to date, and don't open program files received by email or messenger.

References: Microsoft Learn – Protect folders from ransomware with controlled folder access · Microsoft Support – Virus and threat protection in the Windows Security app