This policy setting determines if the Application Guard container, for isolating untrusted files, is pre-created for improved run time performance.
If you enable this policy setting, you can specify the number of days to continue pre-creating an Application Guard container if the user has not opened a file with Application Guard. Pre-creating a container when the user logs in will decrease the wait time when opening an untrusted file.
"65535" will configure Office to always create an Application Guard container when a user logs into Windows.
"20" will configure Office to pre-create the container each time a user logs into Windows for up to 20 days after the last time the user opened an untrusted file using Application Guard.
"0" will configure Office to never pre-create the container. Instead the container will only be created when a user opens their first untrusted file after logging into Windows.
Note: if you configure Office to never pre-create a container then users will experience a longer wait when opening an untrusted file after logging into Windows.
If you disable or don't configure this setting, Office will use a built-in heuristic to pre-create the container.
Note: This policy setting only applies to Microsoft 365 Apps for enterprise.