End Task

You don't necessarily need to shut down your PC each day. Electronic components tend to have a longer life when they are kept at a constant temprature. But, if you do chose to shut down, always sign out of Messenger BEFORE you shut down. In fact, you should close any apps you're using before you shut down. That message is basically asking you if you want to shut down Messenger.

Also, you can check your email from https://login.yahoo.com . You don't necessarily need Messenger, it's just nice to have. The web site has a trimmed down version of it.