Do not open files in unsafe locations in Protected View
This per-user `REG_DWORD` value determines whether PowerPoint opens files from locations classified as unsafe in Protected View.
since 0.9.8.11
Purpose
Show registry keys (1)
HKCU\software\policies\microsoft\office\16.0\powerpoint\security\protectedview\disableunsafelocationsinpv
This per-user REG_DWORD value determines whether PowerPoint opens files from locations classified as unsafe in Protected View.
A value of 1 causes files from those locations to bypass Protected View for this particular trigger. PowerPoint opens them in its normal application environment unless another security control restricts the file. A value of 0, or an absent value, retains Protected View for files opened from unsafe locations.
When no additional unsafe locations have been defined, the Downloaded Program Files and Temporary Internet Files folders are treated as unsafe. Administrators can designate additional local or network folders as unsafe locations.
Notes
Security
A value of 1 removes a layer of protection from files stored in these locations. Protected View normally opens untrusted files in a read-only state with most editing capabilities disabled. Bypassing it causes the presentation to be processed immediately outside that restricted environment, potentially giving a malicious or manipulated file greater access to the capabilities of a regular PowerPoint session.
This setting does not by itself enable macros, ActiveX content, or every other form of active content. Macro policies, File Block settings, Office File Validation, and other security controls continue to apply independently. On supported systems, Application Guard for Microsoft 365 can also provide document isolation in place of Protected View.
Notes
The value is user-scoped and applies only to PowerPoint in the Office 16.0 product branch. Microsoft continues to use the “Microsoft PowerPoint 2016” administrative-template category for Microsoft 365 Apps, Office 2019, Office LTSC 2021, and Office LTSC 2024.
The policy controls only the unsafe-location trigger. A file can still open in Protected View or another isolated environment—or be blocked entirely—for a different reason, such as its Internet-zone origin, its status as an Outlook attachment, a File Block policy, or an Office File Validation failure.
Microsoft documentation
Microsoft Support: What is Protected View?
Microsoft Download Center: Administrative Template files for Microsoft Office