There are two drivers for the DTU-1031X. One is the Wacom tablet driver for the pen digitizer. The other is a video-over-USB (MCT) driver since the DTU-1031X uses USB to transmit the video signal instead of using a separate video card and cable.
The pen tablet driver and the very latest video-over-USB (MCT) driver are available here on this page:
On the Product Resources page just enter the product code into the search field and select your model from the drop down list.
If you are using a previous model, please check here: