After Microsoft Office Live Meeting has been installed open it and then click on the little down arrow in the top left hand corner and then click on Open User Accounts

 On the next screen click on Advanced...

 Place a tick next to the option Use these servers and then enter the following settings:

Internal Server name or IP address: sip.msexchange2007.com:443
External Server name or IP address: sip.msexchange2007.com:443

Select the option for connect using: TLS

Place a tick in the option Use the following user name and password and then enter your username and password into the appropriate fields.