How can I prevent my Exchange Instant Messaging (IM) users from connecting to MSN Messenger?
As the Exchange IM service becomes more popular, companies are deploying it more widely, including companies that don't allow services such as MSN Messenger and RealNetworks' RealAudio on their corporate networks. Microsoft is already wise to this trend and has included a feature in the MSN and Exchange IM clients that lets you turn off connections to MSN. To activate this feature, create a new ExchangeConn DWORD value under the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MessengerService\Policies registry subkey. Set ExchangeConn to 2 to allow only Exchange Server IM connections, to 1 if you want to allow MSN connections while keeping Exchange as the primary connection, or to 0 for the default connection to MSN first, then Exchange. The Microsoft article "XFOR: How to Configure Instant Messaging Client System Policy Settings" (http://support.microsoft.com/default.aspx?scid=kb;en-us;q264472) describes other settings you can tweak to control IM client behavior (including turning automatic updates on or off). However, the article doesn't point out that you can package these settings as Windows 2000 Group Policy Objects (GPOs) so that they're automatically applied to all of your Win2K workstations. (You can achieve the same thing in Windows NT, Windows Me, and Windows 9x by using those OSs' system policy tools.)