The amount of contacts you can have on Windows Live Messenger is 600.
quote:
Originally posted by http://www.microsoft.com/presspass/newsroom/msn/factsheet/WLMessengerFS.mspx
Include more contacts. Users can now have up to 600 Messenger contacts (as well as their other unified, non-Messenger contacts) in their list. Contacts in a user’s Windows Live Mail or Hotmail Address Book will also be added to the Messenger contact list for easy access.
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