That blocking thing must be your firewall.
Go to control panel>system>firewall and disable it, then it wont block your IRC anymore.
Also thats mIRC probably what you have, thats why you have a 31 trial, dont worry it will work after 31 days too, you will just have to wait a bit at the starting screen.
Also you can try other irc clients too like xchat, ice chat, chatzilla, kvirc etc.