Controlled folder access is designed to protect your valuable data from malicious apps and threats, such as ransomware. This feature works by checking apps against a list of known, trusted apps and blocking unauthorized or unsafe apps from accessing or changing files in protected folders.

In Windows 10 or 11 turn on Controlled Folder Access to protect your important local folders from unauthorized programs like ransomware or other malware. Get ransomware detection and recovery with Microsoft 365 advanced protection.

Controlled folder access is designed to protect your valuable data from malicious apps and threats, such as ransomware. This feature works by checking apps against a list of known, trusted apps and blocking unauthorized or unsafe apps from accessing or changing files in protected folders.

Allowing access to your file system might give apps access to personal content that you want to manage. This is why we give you control over the files you share by letting you choose which apps you'll allow to access your file system.

In Windows 11, use the Privacy page to choose which apps can use a particular feature. Select Start > Settings > Privacy & security. Select an App permission (for example, Location) then choose which apps can access it. The Privacy page won't list apps with permission to use all system resources.

If you're worried about a specific file or folder on your local device, you can right-click the file or folder in File Explorer, then select Scan with Microsoft Defender.

How to access and change the privacy settings in Windows 10 and 11.

After you have set permissions for a library, you may want to set unique permissions on one or more folders in that library. For example, you may want to create a subfolder where anyone could read and add files to a subfolder, but not the root folder or any other subfolder.

Learn how to stop sharing your files and folders on OneDrive. You can lock a document, disable sharing links, or stop sharing with specific people.

Learn how to protect your device with Windows Defender SmartScreen and other app and browser control settings in Windows Security.