You need to enable mIRC's built in Identd server
to do this go into mIRC Options (ALT+O) > Connect > Identd
check the box labled [ ] Enable Identd Server
or the box labled [ ] Enable only when connecting
and make sure to fill in the information, just put your nick into the user id spot, System: defaults to unix, and port should be 113
you must do this before you attempt to connect.
Cobra^