Thank you for your question. This forum is for Live Meeting in conjunction with the Business Productivity Online Services. Your question would probably be best answered somewhere within this page
http://windows.microsoft.com/en-US/windows/help/community depending on what versions of Windows and Media Player you are running.
Vickie - BPOS Technical Support
Got an Office 365 question? Try the Office 365 Community Forums http://community.office365.com/en-us/f/default.aspx