The Fall Creators Update includes a new OneDrive feature called “Files On-Demand”, in which your PC now shows “placeholder” copies of your OneDrive files. When you or a program accesses them, they’re downloaded as needed. That way, even if you have 1 TB of files in your OneDrive, they can take up almost no space on your PC, and you can still browse through them in File Explorer.
This is basically the placeholder files feature found in Windows 8.1, but better and without the compatibility problems that led Microsoft to remove it. Of course, Dropbox and Google Drive are now rolling out similar features as well.
How to Enable (or Disable) Files On-Demand
OneDrive now seems to automatically enable this feature. You just have to sign into OneDrive with your Microsoft account. If you sign into your PC with your Microsoft account, you’ll be automatically signed in. If you don’t, you need to launch the OneDrive application from your notification area—it looks like a cloud icon—and sign in.
To confirm that OneDrive Files On-Demand is enabled, right-click the OneDrive icon in your system tray and select “Settings”, or left-click the icon to open the popup and click the gear icon.
On the Settings tab, check that “Save space and download files as you use them” is enabled under Files On-Demand.
If you don’t want to use this feature and want all your OneDrive files downloaded to your PC—so you can more easily back them up or ensure you have all of them available offline, for example—you can disable this feature and OneDrive will behave like it used to. You still have the option to selectively sync folders, if you like.
If you don’t see the option here, your PC probably hasn’t been upgraded to the Fall Creators Update yet.
If you have upgraded to the Fall Creators Update and still don’t see the option, you don’t have the latest version of OneDrive yet. Microsoft is slowly rolling out the OneDrive update for some reason. To get it now, download the OneDrive setup application from Microsoft and run it.
How to Choose Which Files Are Available On-Demand
OneDrive doesn’t necessarily show all your files and folders in File Explorer. To choose which it shows, click the “Account” tab in the OneDrive settings window and click the “Choose folders” button.
This window allows you to choose which files are visible in the OneDrive folder on your PC. You can click the “Make all files available” checkbox and all your OneDrive folders will be visible in File Explorer. You can uncheck folders here to hide them from File Explorer, if you like. They won’t appear in File Explorer on your PC, but will be available online in your OneDrive storage.
How to View Which Files Are Online and Which Are Offline
All your OneDrive files will now appear in File Explorer. Open File Explorer, select OneDrive, and you can browse through everything stored in OneDrive.
There’s a new “Status” column that appears only in the OneDrive folder. This shows you the status of your files and folders—whether they’re “Available when online” (the cloud icon), “Available on this device” (the green checkmark), or “Syncing” (the blue refresh icon or progress bar). You can also mouse-over these icons to see a tooltip explaining what they mean.
To open a file, just double-click it or access it normally in any application. Windows will automatically download it and it will open. As long as you have an internet connection, you don’t really have to worry about where the file is. Of course, very large files may take a while to download, depending on the speed of your connection.
This isn’t just a trick File Explorer is playing, either. Windows presents these placeholder files to applications as normal files, so they should work with every application. Even if you access a file in your OneDrive with a command-line tool, the tool will be able to find that file and Windows will immediately start the download.
How to Manage Which Files Are Stored Offline (and Which Aren’t)
While OneDrive attempts to automatically manage which files are stored on your PC and which aren’t, you can also manage this yourself. For example, you may want to tell OneDrive to download some important files so know you’ll have them when you’re offline. Or, you may want to tell OneDrive to free up the space used by a large file you no longer need on your device.
To do this, right-click a file or folder in OneDrive and select the “Always keep on this device” or “Free up space” option. If you select “Always keep on this device”, OneDrive will download the file to your device and will never automatically remove it to free up space. If you select “Free up space”, OneDrive will remove the file from your local device immediately but it will remain accessible online and will be redownloaded if you access it again.
How to Control Which Applications Can Download Files
Whenever any application other than File Explorer starts a OneDrive file download, you’ll see a popup notification informing you the application downloading a file from OneDrive. The notification will display the name of the file being downloaded and the download progress. If you don’t want the application to download the file, you can click “Cancel download”.
If you do click this button, Windows will warn you that cancelling a download could make the program unstable. The program probably isn’t expecting the file to not open, and it may or may not be prepared to handle this in a clean way. The application may crash and need to be re-opened.
To cancel this particular download, click “Cancel download”. To cancel this download and prevent this particular application from downloading files in the future, click “Block app”.
You can manage app you’ve blocked from automatically downloading files from the Settings > Privacy > Automatic file downloads screen. If you’ve blocked apps, you can click the “Allow” button to unblock all apps. If you haven’t blocked apps, the “Allow” button will be grayed out.
Unfortunately, Windows doesn’t just show you a list of blocked applications and allow you to manage them. So, if you want to unblock a single app, you have to unblock all apps.
This feature makes that 1 TB of OneDrive storage offered with Office 365 subscriptions easier to use and more flexible. Even if you’re storing a lot of files in OneDrive, they won’t automatically sync to all your devices and fill up their local storage.