After getting annoyed with Intel for their lack of willingness to support touchscreens on a collage display:
I have come up with a solution which works really well. The trick is to get yourself an EDID Manager - this tricks the graphics software into just seeing a display and not a touchscreen (it is a bit of hardware which goes between the PC and the touchscreen). However, it is not all as plain sailing as that - the calibration of the screen will be across both screens, so you'll need to recalibrate the touchscreen. As I'm using an ELO touchscreen, I downloaded their utility. In this, under Common Settings, is a tick box to allow the use of screen spanning. Then, when I calibrated the displays, I specified the layout (2 rows, 1 column in Landscape...oddly), and proceeded to calibrate the screens, skipping the non-touchscreen.
Works really well, but may need some trial and error in the different scenarios.
Thank you for posting in the Intel® community and for the feedback and testing performed, I hope this information will be helpful for other community peers.
Intel Customer Support Technician
Under Contract to Intel Corporation