So far I have been able to get Energia running well on Mac OS (less than 5 minutes including download time) and Windows XP (NOT less than 5 minutes :-)).
In my experience downloading and installing (attempting to at least) the drivers from the Energia Windows instructions page does not work. Can't communicate with the device.
I was able to get it to work by downloading the Stellaris drivers directly from TI and following their installation instructions.
What you need can be found at the TI Stellaris® ICDI Drivers page.