If you have the box connected, try opening a notepad text file and hitting the keys--what do you see appear? And/or, if you run any of the basic DirectRT reaction time samples that use "rt:any" (like "text.csv" in the first samples folder) you can click on the buttons you want to proceed from any stimulus. If you look at the data file that is produced, it will show you the keycodes for the buttons you pushed. As far as recording the correct response, you just need to list the "correct" code first in your input file. E.g., with "rt:3,5" the correct answer would be keycode 3.

Hope that helps!
Blair