Hard Reset ASUS T200TA Transformer Book

First method:

The tablet must be turned on, so hold down the Power key for a short while.
After that, swipe in from the right edge of the screen in order to select Settings.
Then tap Change PC settings and choose Update and recovery.
In this step select Recovery.
Afterwards search and choose option Remove everything and reinstall Windows.
When the appropiate information pop-up comes up tap Next to begin the process.
Success! After about 30 minuts your tablet is ready to use.