The installation of irssi in windows is straight forwards.
In this tutorial we are using the latest irssi 0.6.8.15 found here
Download the .exe file and run it, you should see something like that:

Once irssi is installed search for Irssi (in Cygwin) in your start menu and run it.


You will see something similar to the following:


Now because we are using irssi in windows, irssi's Perl functionality, /help and /away commands may exhibit weird behaviors. To ensure that these functionalities work properly, we need to run the following irssi commands:

/set awaylog_file ~/.irssi/away.log
/set help_path share/irssi/help
/set perl_use_lib lib/perl5/5.10/i686-cygwin
/save

Your irssi should look similar to the following.


Next step is configuring our personal settings. You can issue the command /set to see what settings you can change. We are interested in some.
We need to set our nickname with
/set nick Armageddon

Next step is setting our real name with
/set real_name Elijah

Now let's set our user_name also known as identd in mIRC
/set user_name Elijah

You may also want to change other settings, you can look up the menu with PageUP and PageDown to move up and down the page. When done, do not forget to /save the settings.

Now if you like to change any settings of the terminal you have, you can click on the top left corner icon and you will have a drop down menu similar to the following.


Click on "Change Settings" and go to "Appearance" under "Window" and change whatever settings you want there.


If you like to change other settings feel free to do so, press "Apply" when done.

Now let's set up irssi to connect to Beirut Network.
First step is to add the network, we will use
/network add Beirut

If you have an account on the Beirut Network Services you may want irssi to auto authenticate so you can run the following command

/network add -autosendcmd "/^msg NS AUTH Armageddon password123; wait 2000" Beirut

Once we saved the network, we need to add a server to it.
/server add -network Beirut irc.beirut.com 6667 (1)

NB: If you like irssi to connect automatically to Beirut Network you may want to issue this command instead.
/server add -auto -network Beirut irc.beirut.com 6667 (2)

If you issued the first command (1) don't worry, you can remove the server with
/server remove irc.beirut.com 6667 Beirut (3)
Issue this command (3) before you issue (2)

Now we are all set, let's just /save before we continue learning irssi.

Now we need to connect to the Beirut Network.
/connect Beirut

Once connected you will see something similar to the following


To join Beirut channel use
/join #Beirut

To part Beirut channel use
/part #Beirut

To open a query window with a person (private message)
/query nick

To close a window use
/wc

To move through windows use Alt with Right or Left arrow, or simply Alt with the window number.

Now let's explain some technicalities, look at the image below, number 2 is in red which means someone called your nickname there. Number 3 is in white means someone talked in there and Number 4 and 5 are in blue which means one of those join/part/kick/ban/mode actions occured.


Note: For users who want "Arabic" font support, please do the following: (or refer here)
1- In irssi window, perform this:

/set recode_fallback CP1256

/set recode_out_default_charset CP1256

/save

2- GO to "Change Settings" and go to "Translation", change there ISO-** to UTF-8.
3- Save your settings by going to "Change Settings" > "Session" > Type a name/word and click on "Save"

See below screen for more help:




irssi is very straight forward, very customizable and very efficient IRC client once you get used to it.