Keeping any installed apps from accessing data on your file system will be getting pretty straightforward and easy to achieve on next version of Windows 10 in 1803. With a single toggle switch, you can lock it down on the entire system level or on the individual app level, giving the end-user a bit flexibility while strengthening the privacy the same time.
To disable all apps from accessing the file system
Open Settings app, go to Privacy and File System, which is located at the bottom of the left pane.
Then on the right side, click on the Change button under Allow access to the file system on this device.
A little dialog box pops up, switch off the toggle switch. It’s turned on by default.
Once it’s off, it disables all apps from accessing to the file system on your Windows 10 system.
To disable access individually
If disabling the whole file system is too strict, you can control the access individually on single app level. To do so,
Again, open Settings app and go to Privacy and File System. On the right side, switch off the toggle switch under Allow apps to access your file system.
Once it’s off, you can control the individual app file access from the app list below. Every single one of them has its own toggle switch that you can turn it on or off.