hey i have net tools 4, it looks pretty good but i don't think it works :|

i tried the udp flood and the xtgreme udp flooder on my friends IP but i don't think it didn anything to him,.
i even tried to do it to myself, but it still didn't crash me, how do i get this flooding thing to work. i also tried port scanning, and flooding his 25, and **0 ports, NOTHING works