Warning: File History, like Storage Spaces, can be very buggy in the Consumer Preview version of Windows 8. For this reason, you should not rely on either feature to protect your most critical data.
Windows 7 included a very well-hidden feature called Previous Versions that allowed you to recover an older version of a document or other data file. Previous Versions was Microsoft's attempt to create a usable front-end for a service called Volume Shadow Copy that debuted in Windows Server 2003. But since most users didn’t didn't even know it existed, it can't arguably be called successful. Fewer still know that Apple copied this feature and created a prettier version called Time Machine. Sure, you've heard of that.
Well, Windows 8 includes a new feature called File History that attempts to right the wrongs of Previous Versions by offering the same capabilities in a far easier to discover and use package. Apple fans will note that it works, in fact, a lot like Time Machine, albeit without the gratuitous animations and spacy theme. Fair enough.
More to the point, File History differs from its predecessor in some key ways. First, it isn’t enabled by default for some reason, so you’ll need to turn it on. Second, while File History can use a secondary disk or network-based storage to store its backups, it also caches information to the primary disk, so it will work even when you're away from the office with a portable computer. And finally, File History is much easier to use than was Previous Versions. Even if you did use this feature in the past, you'll never miss it.
What File Backup backs up
By default, File History automatically backs up everything in your libraries, desktop, Favorites, and contacts. That's a lot of stuff, when you consider that your libraries include several folders, even in a base install of Windows 8: My Documents, Public Documents, My Music, Public Music, My Pictures, Public Pictures, My Videos, and Public Videos.
But File History is actually more sophisticated than that. If you make your own libraries, as some power users might, even those libraries are backed up automatically: File History backs up all libraries, not just the built-in libraries. And you can exclude folder locations if, say, you don't need this feature backing up videos or other files.
File History can also be used as a replacement for Windows Home Server's centralized PC backup functionality, sort of. While it doesn't offer centralized image backup functionality like WHS, that feature isn't really needed in Windows 8 because the system is so easily reset with Push Button Reset. Instead, File History can advertise its location to other users and PCs in your local homegroup, creating a centralized spot for these backups. So you might use your desktop PC with its ample storage as the central location for File History-based backups for all the PCs in your homegroup.
Configure and enable File Backup
File History is implemented as a classic control panel. (The fastest way to access it is to first display Control Panel via the new power user menu (mouse into the lower-left corner of the screen, right-click, and select Control Panel) and then search for File History using the pre-selected search box.
You can configure File History to use a secondary hard disk or other storage device if available. Otherwise, it will recommend network storage.
Available configuration options include:
Change drive. If you’re not happy with the drive that File History selected, or would at some point like to change the location for backups, click this link to select a new one. The resulting page will help you select a new disk, if one is available, or a network location. (File History will ask you if you'd like to move existing backups, which is a nice touch.)
Exclude folders. If you would like to exclude certain folder locations from being backed up, you can do so here. Remember that everything in your libraries, desktop, Favorites, and contacts is backed up, so be sure to pick a folder inside one of those locations since other locations are already omitted.
Advanced settings. This interface provides fine-grained control over key File History functionality. You can change how often files are backed up, the size of the offline cache (which is the size of the File History backups replicated on your system disk), and the length of time to save backups. You can also use this interface to clean up (i.e. delete) older backups and advertise your backup location to others on the homegroup.
Where File Backup really shines: The new recovery interface
File History offers two basic approaches to file version recovery: You can simply launch the File Backup control panel, click the Restore personal files link, and navigate through a virtual view of your file history starting at the Home location.
This works, but most often you are looking to restore a version of a very particular file. So instead of this brute force approach, you can simply click the History command in the Windows Explorer ribbon to launch the File History recovery interface from the actual location of the document. This will make it much easier to find what you're looking for.
Either way, File History provides simple navigation, with the ability to, yes, "go back in time" and recover previous versions of files. You can recover to the current folder, and choose whether to overwrite current file versions, or recover to a different location using the Options menu.
Final thoughts
I suspect that many power users are already contemplating how they can use Storage Spaces and File History together to create a two-way mirror or better on a well-equipped desktop PC and then share out that space as the central location for File History backups for all the PCs in the house. This should enhance the resiliency of all of your backups, no matter which PC you use on the home network. And it might even make you forget all about Windows Home Server, you never know.
Regardless, File History looks like a very interesting feature and one that does indeed erase most of the issues with its predecessor, Previous Versions. Taken in tandem with the many other disaster recovery technologies in Windows 8, a complete picture emerges of how Microsoft intends to keep our vital data safe through the years ahead.