How to prevent Teams from registering as the chat app for Office? It re-enables itself

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Is there a way of preventing teams from registering as the chat app for Office, and sticking to that setting? It keeps re-enabling by itself after each restart of the application.




I know that there is a registy key for this one: HKEY_CURRENT_USER\Software\IM Providers\DefaultIMApp , but I want to avoid locking it in registry, just in case of future changes required.


So, is there an option to prevent this behavior? 

9 Replies



If you are running in TeamsOnly coexistence mode it will be set as chat app for office so what coexistence mode are you running? 

@Linus Cansby 


The check box displayed returns even after clearing and restarting Teams.  You are saying that in coexistence mode it will do that?  Seems like the default in Windows 10 for DefaultIMApp in registry is whatever app starts last.  So, to understand, if I remove coexistence mode, Teams will not change the registry key?

@dlee1 Which app do you want registered for chat ? If you are in Teams only then Skype is just an ornament so it always enables Teams.

@Steven Collier Appears that last program to start is the default.  We are currently using Jabber over others.  That I hope will change, but I need Teams to stand down for the time being.  We had been using S4B, but recently changed to Teams only.

Hi dlee1,

Did you ever have any luck with this?
I have the same issue, Jabber is our corporate app for chat, but I need to take teams out of island mode as we want to start utilising the external sharing features.
Short of locking the registry key down (Which I would rather not do) I can’t find a way..
Is there an update to this topic? or a better solutions? i have the same issue.. Teams is in a PoC state...with just a few clients. (Islands) and as long SFB is the primary tool inside the company, presence inside of outlook should come from SFB and not teams.
After starting Teams up (e.g. reboot), the tickbox "Register Teams as the chat app for Office " is ticked again. To ask the user to untick it and stop/start all office applications is kind of no option.

@BartoszS  Same for us. Office 2019 - no more MS teams as a default chat app for office... rubbish software...

@Peterhawke were you able to find a solution for this issue of Teams overwriting Jabber for the default Chat app?  I am running in to the same issue.

Did you ever find a solution? Trying to do the same thing.