I don't seem to be able to locate the download of ICDI drivers for Tiva C Series LaunchPad.
Starting from http://www.ti.com/tool/ek-tm4c123gxl, I clicked on Stellaris ICDI Drivers under Software. The link brought me to http://www.ti.com/tool/stellaris_icdi_drivers. At the page under Software is the Stellaris FTDI Drivers link http://www.ti.com/tool/lm_ftdi_driver. I downloaded the FTDI driver and it is not the driver for Tiva C Series LaunchPad EK-TM4C123GXL. When I tried to install this driver, it did not work.
I dug into my computer to find a copy of the Stellaris ICDI Drivers download and it installed fine.