This policy setting controls whether text-based files (.csv, .dif, and .sylk) opened from an untrusted location are always opened in Protected View.
If you enable this policy setting, text-based files opened from an untrusted location are always opened in Protected View. Users will not be able to change this setting under File > Options > Trust Center > Trust Center Settings > Protected View.
If you disable or don't configure this policy setting, text-based files opened from an untrusted location are not opened in Protected View, unless users have changed this setting in the Trust Center.
Note: This policy setting only applies to subscription versions of Office, such as Microsoft 365 Apps for enterprise.
| Registry Hive | HKEY_CURRENT_USER |
| Registry Path | software\policies\microsoft\office\16.0\excel\security\protectedview |
| Value Name | enableforeigntextfileprotectedview |
| Value Type | REG_DWORD |
| Enabled Value | 1 |
| Disabled Value | 0 |