The tasks to force removal of Exchange 2013 are:

The most common reasons are listed below:

  • The deinstallation didn’t finish properly and left attributes or entries in Active Directory
  • The Exchange server is permanent offline and Exchange should be removed
  • An Exchange installation didn’t finish properly and the attributes and entries should be removed

To remove the server open ADSIEdit and go to configuration

On ADSIEDIT:

CN=Configuration,DC=MYDOMAIN,DC=LOCAL
CN=Services
->; DELETE
CN=Microsoft Exchange
CN=Microsoft Exchange Autodiscover

CN=Default naming context,DC=MYDOMAIN,DC=LOCAL
->; DELETE
CN=Microsoft Exchange Security Groups
CN=Microsoft Exchange Security Objects

IIS: Start inetmgr
DELETE the Exchange Back End and Front End websites with the IIS-Manager:

autodiscover
ecp (-> Exchange Control Panel)
EWS (-> Exchange Web Services)
Microsoft server Activsync (-> Exchange Active Sync)
OAB (-> Offline Addressbook)
owa (-> Outlook Web App)
Rpc (-> Remote Procedure Calls)

etc…

Also don’t forget to remove the application pools (MSExchange*)

Certificates:

Remove the local computer certificates (MMC, certificates snap-in, computer store)

AD Users and Computers:
DELETE the following users in the “Users” container:

DiscoverySearch Mailbox{GUID}
Exchange Online-ApplicationAccount
FederatedEmail.GUID
Migration.GUID
*SystemMailbox{GUID}
*HealthMailboxGUID

Registry:
DELETE the key “ExchangeServer” under:
HKLM\Software\Microsoft

DELETE the keys “MSExchange*” under:
HKLM\CurrentControlSet\Services

Hard Disk directories:
On the server’s hard disk you’ve to DELETE the Exchange Server installation folder.
Usually it’s C:\Program Files\Microsoft\Exchange Server

and c:\ExchangeSetupLogs

remove also d:\ mailboxes or other Exchange logs / monitoring directories

Cleanup Recycle bin

Final reboot