Files from the internet and other potentially unsafe locations can contain viruses, worms, or other kinds of malware that can harm your computer and data. To help protect you, Office opens files from potentially unsafe locations in a secure container that's isolated from the device through hardware-based virtualization. When Office opens files in Application Guard, you can securely read, edit, print, and save those files.
If you believe the file is safe, you can choose to open the file outside of Application Guard.
How do I enable Application Guard?
Application Guard is currently in limited preview, and we're expanding the preview to include more customers. If you're interested in participating, please complete this form. Thank you for volunteering to participate in the preview, and we apologize if we can't enroll everyone at this time.
When will Office use Application Guard to open files?
Office will automatically use Application Guard to isolate untrusted documents under the following conditions:
Application Guard is enabled in Windows. This can be enabled by either an administrator deploying policy or the user.
The user is using an Office 365 ProPlus client.
The user signed in to Office is licensed for Application Guard. Application Guard for Office will require either a Microsoft 365 E5 or Microsoft 365 E5 Security license.
If any of these conditions is not met, Office will use Protected View to isolate untrusted documents.
When will a file open in Application Guard?
Files that currently open in Protected View will open in Application Guard. These include:
Files originating from the internet: This refers to files that are downloaded from domains that aren't part of either the local intranet or a Trusted Sites domain on your device.
Files that are located in potentially unsafe locations: This refers to folders on your computer or network that are considered unsafe, such as the Temporary Internet folder or other folders assigned by your administrator.
Outlook attachments: Attachments in email can come from unreliable or unknown sources, such as someone outside your organization. Sometimes malicious attachments can appear to come from trusted senders or compromised accounts of trusted senders. Always confirm with the sender if you receive an unexpected or suspicious attachment via email.