I just learned there are several types of WebTV boxes. I have never seen or 
used one and the information below is based on what I hear from WebTV users. 
Please tell me if my ingo needs an update! 

I'm sorry to inform you that to the best of my knowledge there is no way to 
use mIRC on your WebTV box. mIRC is made for PC's with MS Windows. I have no 
idea if your WebTV box runs some form of Windows but you there seems to be 
NO WAY to install your own software, like mIRC, on it. (I think WebTV boxes 
do not even have a harddisk?) There is no way around this unless WebTV chooses 
to 'improve' their hardware significantly. If you really want to use mIRC you 
better not wait for that to happen and buy a PC! 

In the mean time you're not totally lost. You CAN join IRC with your WebTV box. 
At http://irchelp.org/irchelp/misc/webtv.html you will find an excellent 
information page about WebTV and Internet Relay Chat by Ngan Bui (Ariell) and 
Joseph Lo (Jolo), with help from FraN2k and ExPeaches. I strongly advice you 
to read this page! You could also try WebTV's IRC Help page at 
http://wecare.webtv.net/features/community/irc/ 

By default WebTV users can chat on Talk City, one of the largest web-based 
chat servers. These servers are like the tip of the iceberg compared to the 
much larger and more exciting IRC networks. To reach other IRC networks, you 
need to know the address of a server on that network, the port number, and 
the channel name. You may not be able to access all networks or servers due 
to restrictions placed on each server to limit the kind of people who can 
connect. After you have this information, do the following:

  1.Return to the Home page 
  2.Select Community 
  3.Select Chat 
  4.Select Go to 
  5.Enter the following: 
       - server address (something like irc.whatever.com) 
       - port number (typically 6667, or you can try 6660 up to 6668) 
       - the channel name (such as #IRChelp) 
  6.Select Connect 

The best way to get additional WebTV-specific IRC questions answered is to email wecare@webtv.net. They forward your question to somebody who actually knows IRC, who then returns your emails within a week. They are pretty detailed in their answers. 

Lots of succes! Have fun with your WebTV box and, who knows, see you on IRC!!

Tjerk.