Step 1 : - Enabling Additional Repositories
Now many applications need additional repositories to be installed or some to be enabled in Synaptic package manager so before trying out steps given below ensure that repositories in order.
Launch Synaptic Package Manager (System -> Administration -> Synaptic Package Manager ) , then in Synaptic package manager go to (Settings -> Repositories ) you will find window like this . Ensure that all the check boxes are marked leaving source code(if you want to you can enable this also but you are not going to need this unless you are software developer) the dialog box should look like this .

After completing above step you will find a dialog box like this

Besides these you may also like to add medibuntu repositories if you want to install applications like ——- , to add mediubuntu repositories follow the following steps
echo "deb http://packages.medibuntu.org/ gutsy free non-free" | sudo tee -a /etc/apt/sources.list
and
wget -q http://packages.medibuntu.org/medibuntu-key.gpg -O- | sudo apt-key add - && sudo apt-get update
This tutorial i’m gonna share to you will talk about on how to run an IRC (Internet Relay Chat) Channel on Undernet Server. First, we might consider downloading IRC Chat Clients such as mIRC, Pidgin, Xchat and many more. By running an irc channel, we need to have a registered account on undernet. To do this, we should go on their registration site at http://cservice.undernet.org/live/ and click the Create One link on the login form. Follow the steps provided. You also have to provide an email address provided by your Internet Service Provider (ISP) because Undernet won’t accept emails like yahoomail, gmail, and hotmail.
Let us suppose that you have now your registered username. Fire off your irc chat client and set your server to Undernet on random server. You might consider doing it manually by typing on the input bar /server us.undernet.org. Upon connecting to the server, you may get a couple of lines similar to this one:
Connecting to us.undernet.org (6667)
*** Looking up your hostname
*** Checking Ident
*** Couldn’t look up your hostname