Exchange 2016 - Uninstall because of wrong key

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Hello ITPros!
I have a DAG with 2 servers for Exchange 2016 and with lack of atention I licensed on of them with na Enterprise key when I was looking for the standard Edition.
Is not in production yet but it will be soon.

As for what I looked for I need to remove this server and install a new one. Because I'm not that experienced with this I ask if the steps I should take are these (looked online but there is a lot a information that is different):

• Install a new server and install Exchange
• Add the server to the DAG
• Configure database copy on the new server
• Remove the database copy from the server to remove
• Remove the server from the DAG
• Uninstall Exchange 2016

With these steps is everything removed form the AD regaridng this server or there is the need to do some clean up? I'm not sure that we will install this server again to have 3 servers but in that case I would use a new name, just in case something under ADSI -- Configuration stays there.

Online I found that we need to remove data from ADSI but when the servers dies, not uninstalling it.
Thank you again! I'm having a perosnal course sponsored by my company on Exchange but your vídeos will help trying to achieve 70-345.

Have a great day!

@fabio-teles,

If they are not in production, you're not worried about moving mailboxes, etc..

If I were "uninstalling this server" and installing a new one. I would uninstall first before installing the new one.

I did this a while ago under Exchange 2013 or 2014...(hard to remember). But the uninstall link from exchange does a fairly decent job and telling you the steps but it doesn't mean it's all you have to do.

Following the uninstall provided by exchange will remove the product from your OS but not the AD.

For you completely remove that installed exchange server, you may need to run the ADSI edit > right click on ADSI Edit; connect to Configuration and click OK.

Then expand Configuration, CN=Configuration, CN=Services, CN=Microsoft Exchange, CN=<OrganizationName>, CN=Administrative Groups, CN=Exchange Administrative Group
Click on CN=Server

Select the CN=YourExchangeServerName in the details pane, then delete.

Then wait for the changes to replicate through your AD before installing a new exchange server.

Now, my caveat...It's been a while since I've done this...so you may want to explore more the Exchange 2016 documentation for removing exchange from AD.

I hope others will chime in and give a more complete answer than from my previous experience with it.

Thank you for the quick reply!
I will test under a virtual LAB before moving to production.
So I'll give feedback here also.
Thank you for the tip regarding the ADSI!

Hello!
Just to share back to the community. After some testing on a LAB environment (a replica of the official MS VMs for the course) I successfully uninstalled Exchange 2016. There were some steps needed so I share them here:

• Preparing the new server
  Prepare a new server with the same partitions, disks, DAG network, etc.
  Configure the DAG NIC (IP address)
  Add server to the DAG
  Verify the replication network
  Test everything (created a new DB on the server, and then added the copies of the existing DBs)

Removing the server
Migrate mailboxes if they are on local DBs on the server that we are going to remove
Move databases to other server (depends on the configuration and built-in accounts)
Activate databases on other servers
Remove database copies from the server
Remove server from the DAG
Restart server
Uninstall Exchange from the Control panel
Restart
Check ADSI if everything was removed

On the LAB environment everything was correctly removed from AD, so Exchange 2016 takes better steps on the removal part. Also some links with information regarding this subject:

https://practical365.com/exchange-server/exchange-2013-how-to-remove-dag-member/
https://social.technet.microsoft.com/Forums/en-US/eef02396-a9b3-472a-b36c-42d96a39a74b/uninstalling-exchange-server-2016?forum=Exch2016SD
https://social.technet.microsoft.com/Forums/en-US/3d0e0d4e-8605-4692-af05-06b480ebc980/uninstall-exchange-2016?forum=Exch2016SD
https://blogs.technet.microsoft.com/exchange/2014/03/17/this-mailbox-database-contains-one-or-more-mailboxes/
http://www.mustbegeek.com/move-mailbox-from-one-database-to-other-in-exchange-2016/
https://www.youtube.com/watch?v=wkTrbrnZjF0
https://markgossa.blogspot.com/2015/12/exchange-2016-database-availability-group-part-1.html
http://itprocentral.com/exchange-server-2016-configuring-dag-network-adapters/
https://blog.devoworx.net/2015/09/04/evaluation-period-expired-for-windows-server-2012-r2-how-to-extend-it/
https://practical365.com/exchange-server/fix-all-failed-exchange-database-content-indexes/

Hope it helps someone with the same need! @Ronnie-Wong again, thank you for the guidance!

@fabio-teles,

Glad you worked it through. It's not as easy as some assume. great job!