Once you have signed in, a new page will load in the same window. This will be either your Windows Live Home page or your Windows Live Inbox page, depending on the preferences that you have selected for your Windows Live Account when you signed up for it. In any case, you will find a “Messenger” tab on the top of the page. Move your cursor to this tab and click on it.
Alternatively you can also use following services to use hotmail messenger without downloading it: