No problem. A bit weird though to have it in the program help information, but again it comes down to the definition of Access Control, under normal circumstances it would mean who can access it.
Assign a drive which can be used to access your aggregated sandbox storage
By default, Windows will assign a specific drive letter which you can then use to access your entire sandbox storage. However, you can select any other available drive letter instead. This is useful if you have multiple storage folders (for example, if storage folders are created on the same drive as the modified file) and allows you to access and manage all of your stored files together, regardless of their actual location.
Not having the Sandbox, I don't know if that just allows you to access the sandbox folder (normally hidden) or something else, like the bit I have in
Red Italics in the quote above, especially the part about Manage. Does that mean you could subsequently extract files from that location to the regular desktop
As it says in the Mount automatically at startup:
Mount automatically at startup
If you assign a new drive letter for accessing your aggregate sandbox storage, you can apply (mount) the new drive immediately, or when your computer is next started.
To me that gives the impression that like a disk image in backup software, you can mount the image so that it looks just like it would under windows explorer as other folders, rather than what the sandbox storage is, hidden and encrypted.
One thing for sure it need some avast input, probably from pk.