Well some symptoms seems to be the same I had with my touchscreen. But some don't

On my ts the drivers did load, but the calibration was messed up to either vertical or horizontal direction. After recalibration it worked fine. Also I could suddenly hear the sound Windows makes when USB devices are connected or disconnected. After those sounds I'd know that TS wouldn't work.
To keep long story short - my problem was the USB cable. I replaced mine with direct usb cable straight from the touchscreen controller pcb. My screen was 7" Lilliput 619 with screw type connector.