Windows Live Messenger (New!) is an instant messenging program that allows you to send and receive instant messages, hold video chats, and share files. Windows Live Messenger doesn’t come installed with Windows Vista, so you need to download and install it from the Microsoft Web site. Before you can use Windows Live Messenger, you need to get an account ID. You use the ID to sign-in to Windows Live Messenger as well as other Windows Live services, such as Windows Live Mail and Windows Live Spaces. If you already have an MSN Hotmail, MSN Messenger, or Microsoft Passport account, you’ve already got a Windows Live ID.