So you did not manage to install Windows 7 then? Or it is just the touch screen on Windows 7 that doesn’t work?
If it’s the touch screen, maybe you can try to find the Windows 7 touch driver for the Toshiba ST-A20 (the newer model) or even the Toshiba C10, there is a chance might be using the same touch screen.
Also I saw this old post on the forum, not sure the end result but might be worth checking with the user or posting on that topic as well to see if there was any more info available. He only appeared to have a problem with the pole display, however it’s possible he was using SambaPOS V3 and therefore was still using Windows XP.