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Every once in a while a request to install to a drive other than C:\ comes along. Generally, I am happy to comply. Its when the request comes through AFTER I have already done the installation that makes for interesting times.

On the surface you would think that simply uninstalling all the Skype components, followed by a reboot and re-install would do the trick. Is anything ever that simple?

Lets give it a crack and see how we get on.

I would recommend that you have a backup handy before attempting this, although the data is stored in the CMS which we are not touching. Rather safe than sorry, besides, what could possibly go wrong?

  1. Stop all Skype for Business Services
2. Off to Programs and Features on the Skype Front End to Uninstall all items relating to Skype for Business

Uninstall Skype for Business

3. Always good to do a quick reboot when uninstalling bits

4. Now, by launching the setup from the installation media we should see the option to install to a directory of our choice.

Front End Install Directory.jpg

5. Click install


6. Next you will need to run through Step 1, 2 and 3


Houston we have a problem! Running through step 1 was no issue, but when running through Step 2:Setup or Remove Skype for Business Server Components we got the error below


HostLocalActivateTask execution failed on an unrecoverable error

Unrecoverable, mmm..that sounds serious..

Taking a dive into the log file (just click View Log) we find the following error

RTCCAS Already in use

Fair to assume that there are some RTC components that have not been removed from my uninstall attempt as evidenced by this error message. If you head of to services.msc you will see the services in question. Looking at the properties of the service I am able identify that it is indeed RTCCAS in my case.


That’s OK as we can manually remove the culprit services. There are a number of services labelled RTCxxx

To delete the services which are tripping up the setup wizard because they already exist do the following:

Run command prompt (CMD) as administrator

Run the following command
sc delete RTCxxx

(In my case RTCxxx is RTCCAS as seen in the log file and in my services window)

Reboot the server and continue the installation by running through Step 2:Setup or Remove Skype for Business Server Components

That should be it, however if you are still seeing the “HostLocalActivateTask execution failed on an unrecoverable error” you may need to delete additional services. All the RTC services are listed below:-

RTCSRV Skype for Business Server Front-End
RTCAA Skype for Business Server Conferencing Attendant
RTCAS Skype for Business Server Conferencing Announcement
RTCRGS Skype for Business Server Response Group
RTCCPS Skype for Business Server Call Park
RTCATS Skype for Business Server Audio Test Service
RTCIMMCU Skype for Business Server IM Conferencing
RTCDATAMCU Skype for Business Server Web Conferencing
RTCAVMCU Skype for Business Server Audio/Video Conferencing
RTCASMCU Skype for Business Server Application Sharing
RTCMEDSRV Skype for Business Server Mediation
RTCCLSAGT Skype for Business Server Centralized Logging Service Agent
RTCHA Skype for Business Server Health Agent
MASTER Skype for Business Server Master Replicator Agent
REPLICA Skype for Business Server Replica Replicator Agent
RTCXMPPTGW Skype for Business Server XMPP Translating Gateway

You should now be able to proceed to Step 3: Request, Install and Assign Certificates

Since we didn’t remove any Certificates the only missing Certs should be the Default.

Default Certs

No need to request again as the default certificate should still be in the certificate store and will simply need to be assigned. Click on Assign , select the default certificate and finish the wizard.

Assign Certificate

From here on you should be able to start the Skype for Business Services and all the configuration data should be available. A quick check on the install directory shows that the installation has been “moved”.

New Install directory

One more check to see if the servers are replicating. Dont forget to start all the services before checking replication.