Windows 8 includes a reset function that restores the operating system to a clean state and scrubs data applications from the disk, but falls short of making that data unrecoverable, according to Microsoft.
The operating system, now available as a developer's preview, can also refresh itself, restoring the operating system to its original state while also saving data and applications, according to the Building Windows 8 blog.
When Windows 8 resets itself the data it removes can be erased more thoroughly than in a traditional reformatting of a disk by overwriting every sector, Microsoft's Steven Sinofsky writes. That doesn't mean it can't be recovered, though. "Even if someone removes the drive from your PC, your data will still not be easily recoverable without the use of special equipment that is prohibitively expensive for most people," he says.
He says the optional "thorough" reset adds additional purging steps that limit the effectiveness of recovery attempts. It does not replace "multi-pass scrubbing operations that might be required for regulatory compliance if you are dealing with highly confidential business and government data," he says.
The thorough reset is suitable for scrubbing a machine that is being recycled or donated to a charity because it makes data recovery harder and because it's quick compared to more thorough methods that take hours, Sinofsky says. Reset with Bitlocker disk encryption disabled takes about 24 minutes. With Bitlocker, it takes about six and a half minutes, Sinofsky says.
The refresh option is meant for fixing operating system problems that may arise without risking data already stored on the machine. "The coolest part about Refresh is there's no need to first back up your data to an external hard drive and restore them afterwards," he says. Refresh is automated to some degree, eliminating the need to run through Windows Welcome screens in order to reinstall the operating system by preserving user accounts and settings as well as account names and passwords. Data and documents appear in the same locations they were before refresh.
Refresh also restores applications based on Microsoft's Metro design language, but not traditional third-party applications. Those have to be manually reinstalled.
Both reset and refresh rely on Windows 8's underlying setup engine that the company touts as making it simpler to deploy the operating system in business settings on many machines.
Windows 8 gives users the option to capture an image of the hard drive as they have customized it. So if they want to remove applications that come with the operating system or to include applications they have added, they can do so. Those images are stored and can be used as the baseline image that the machine restores to under refresh, Sinofsky says.