Hi, I am Dave, I will help you with this.
WDDM is set by the device driver on your graphics card, if your graphics card only supports WDDM 1.3 you cannot upgrade to version 2.0 because your graphics card does not support that.
Click your Start Button, then just type dxdiag and press Enter.
On the resulting DirectX utility, select the Display tab
Please provide a screenshot of that Display tab.