Download the Messenger Beta for Windows 7 and Windows Vista.
With the Windows Live Messenger Beta, the best way to keep your people closer gets even better. Video chat in HD* while you share photos. Get your Facebook and MySpace updates right in Messenger, and just the way you want them. Go mobile and chat on your phone. Get the Beta for your PC running Windows 7 or Windows Vista and be among the first to try the new Messenger.
Messenger Beta is part of Windows Live Essentials Beta, which includes beta versions of Messenger, Photo Gallery, Mail, Movie Maker, Writer, Family Safety, Sync, and Messenger Companion, plus Bing Bar, Microsoft Office Outlook Connector Pack, and Microsoft Silverlight.
Follow this link to learn how to install messenger beta: http://explore.live.com/windows-live-messenger-beta