You have 1 computer with 2 networking cards and that computer is running software to share your internet with other computers that are connected to the same hub you are, correct?
If so, I have no idea how to use that program. I should still be able to walk you through the process if necessary though.. Just msg me on IRC if you need more help..
If you wish to contact me, Type this in your mIRC:
/server -m undernet -i Nick754 Nick4354 email name -j #nltester
I'm any of the names in there with a -NL at the end of it, just type !ping2 in the channel, then msg the one with the lowest response time. (there've been massive server splits on undernet, that's why I'm having you do that)