MSN is Microsoft's Internet service, the MicroSoft Network.
What it is:
It is a chat box where you add hotmail emails to speak to your friends,
You can download it from the internet, add your friends and you can chat together but don't download any smiley faces to go with the MSN as it crashes it. Only download MSN.
Given below where you can download the latest version (it's all safe and free!).