You have the choice to Refresh or Reset your Surface. When Refresh your PC you don't lose any files. When Reset your PC all of your files are removed. Tost be careful!
Important warnings: Things you need to know before resetting Surface. After a reset, Surface returns to its factory settings.
-All your personal files, settings, and apps will be gone. You’ll have to set up Surface as if it were brand new.
-Windows and the apps that came with Surface will be reinstalled as part of the reset process, but you will have to reinstall Windows Store and desktop apps that did not come pre-installed on Surface.
Reset Surface from a USB recovery drive
- Open the Settings charm, tap or click Power, and then tap or click Shut down. (Or, tap or click the Power icon in the lower-right corner of the sign-in screen.)
- Attach the USB recovery drive to Surface.
- Hold the volume-down (-) rocker.
- Press and release the power button.
- When the Surface logo appears, release the volume rocker.
- Choose your language options.
- Choose your keyboard layout.
- From the BitLocker screen, tap or click Skip This Drive.
- Tap or click Troubleshoot.
- Tap or click Reset your PC.
- Tap or click Next.
- Tap or click Windows RT 8.1 as the operating system currently on your Surface to be reset.
- Tap or click No, keep the existing partitions.
- Tap or click Just remove my files.
- When Surface displays All ready to go, tap or click Reset.
Everything went fine in my situation. As long you have a Recovery Drive, you can revert to default in just a few minutes. Just great!