What?  You want to disable IM in Lync?  Why on Earth would you want to do that!

It turns out there are a number of reasons that some organizations might want to, including:

• compliance - don’t want IMs to be archived/discoverable…so don’t have them!
  productivity - perception that IM hurts productivity…
  I believe exactly the opposite is true in most situations

Whatever the reason, there’s a simple way to disable IM via a registry setting on the Lync Client.  It’s actually a hold over from the Office Communicator client, and the setting is described in BLOG post here as well in a KB article (KB954648).

All that’s required on the client machine is:

1. In the registry, create a DWORD value of "1", at location HKEY_CURRENT_USER\Software\Policies\Microsoft\Communicator\DisableIM
2. Start (or re-start) the Lync Client

What happens?  The user can’t participate in IM conversation, using the Lync client, that’s what happens!  One easy way to see the impact is by looking at contact cards before / after the change – the IM “bubbled” is greyed out.

Two pictures of contact cards make the point best:

Before (IM Enabled)    After (IM Disabled)    

-John