Please don't post in multiple places - just one post is fine and will get answered as soon as I can.
Please restart your computer and modem/router first and try to open IrisLauncher.exe again.
If it still closes, reinstall the client with the installer you downloaded before and try it again.
When you say it autocloses, do you mean it just disappears from your screen without any error message or anything? It's very unusual to do that, it would normally give some kind of error message first.