Q. How can I securely wipe data from my Surface device?
A. Microsoft have a Surface Data Eraser tool which is documented at https://technet.microsoft.com/en-us/library/mt605308.aspx and available for download from http://www.microsoft.com/en-us/download/details.aspx?id=38826. The tool works by creating a USB drive which you boot the device from which will then securely wipe the device to Department of Defense (DoD) and National Institute of Standards and Technology (NIST) standards. You need a USB drive with at least 4 GB of free space to create the stick.