Do you have to pay to register? Because on www.mirc.com , it has a button that says "Register mIRC" and you have to pay US#20.00. But here in the TUT, it also say to register, but I don't know if that's for free or not. Or just do that if it's totally free and no trial version. Also, can you delete your IRC account?
I think it's "download irc" and when it the trial expires. Just wait for the continiue button to show.