Live Meeting supports a maximum number of 1250 participants for a single meeting if you have a Professional License and a maximum of 250 participants if you have a Standard License. These numbers include the organizer, the attendees, and the presenters. If you must have more seats than what your license allows for a particular meeting, contact your Live Meeting administrator or the Live Meeting Sales Account Manager.Note
The organizer who sets up a meeting decides the number of participants. For example, if the organizer decides on a size of ten participants, a maximum of ten participants can attend the meeting.
For more details on configuring meetings and conferences using the Office Live Meeting Service Learn About Office Live Meeting
For additional support information for the Office Live Meeting service Office Live Meeting 2007 service support