How to disable instant messaging in Communicator 2007

I know it sounds counter intuitive to disable instant messaging in Communicator but some organizations may have legal or other reasons for disabling instant messaging inside Communicator 2007. You still get presence information and if you are using OC only for remote call control or VOIP, you might not need or want your employees using IM.

In the RTM version of Communicator 2007, it was not possible to disable IM, but with the new July 2008 update, you can!

Once the update is installed, you need to set a registry setting on the client machine. I am hoping they update the group policy .ADM files to include this new functionality (hint hint), so that I don't have to manually add this for my clients.

The registry setting in question:

DWORD value of "1", at location HKEY_CURRENT_USER\Software\Policies\Microsoft\Communicator\DisableIM.

Please note that without KB 954439 installed (the July 2008 Communicator update), the older versions of Communicator 2007 do not know about or obey the registry setting.

The KB article that describes how to disable the IM functionality is KB 954648, and is available online.

Also, somewhat related to this, is the Ethical Walls API example I wrote about here, and that related download is here. In that API example, it allows the administrator to place users into Organizational Units in Active Directory and to configure communication blocks between members of the different Organizational Units.

Update: KB 954439 updates the Communicator client to version 2.0.6362.76, and is online now as of 08-01-2008. You can request it from MS here.

Update 2: Updated registry key to proper location - thanks Russ W.