Exchange 2019 On Prem Install

In a couple of weeks time I’ll be in Brussels presenting at Engage and one of my sessions is Face/Off Domino vs Exchange On Premises (Weds at 8am).  I have an Exchange 2016 install but since Exchange 2019 shipped last October I wanted to update my install with that so I could use the latest version to demo.  In truth very little has changed in Exchange on premises since 2008 but I don’t like using an old version in my presentations.  So this is the story of the 4 days it took me to complete the install.

Four. Days.

Day 1: My big mistake.  I decided to uninstall Exchange 2016 instead of upgrading it. I wanted an entirely clean server to demonstrate.  The uninstall failed half way through.  It wouldn’t uninstall and it was still listed under installed programs.  Several hours of trial and error and internet research confirmed this is a common problem with Exchange uninstalls and the “fix” is to flatten the machine and start over.  The problem was the Exchange install was on the same box as the Active Directory 2016 Domain Controller which I really really didn’t want to flatten.

Day 2: Being Stubborn.  I’d do just about anything to avoid flattening the entire box and rebuilding so some more internet research took me to several blogs that talked about manually removing registry entries in order to clean up the install.  Hundreds of registry entries.  After doing that I still couldn’t delete or rename the folder despite no services being present so then it was into safe mode to do the rename.  That worked and I started the upgrade to Windows 2019 (the only supported platform for Exchange 2019). You can now do an inplace Windows upgrade from 2016 to 2019 and that worked maintaining all my Active Directory settings.

Day 3: Accepting the inevitable. Off I go with an Exchange 2019 install once more which started to install then prompted me for the Exchange installer disk.  It wouldn’t take the mounted disk I had started the installer from.  After a few hours’ research I realised this is a common red herring error that basically means the server can detect some old installation files and won’t complete.  At this point there were no services, no directory, nothing listed under installed programs.  Sometimes you have to accept you’ve strayed too many hacks from your starting point it’s best to startover and do it properly.  Windows 2019 install #2 this time letting it blat the server and rebuilding Active Directory from scratch (luckily it’s just my demo machine and I could do that but good luck if it’s your production environment).

At the end of day 3 I had a new Windows 2019 Domain Controller fully patched and I was ready to start my Exchange 2019 install.

Day 4: The Long Road.  Before Exchange will install the installer program will verify you have all the pre-requisites required on the operating system.  There are many from IIS management tools to .Net 4.7.1 to the basic authentication system.  A scrolling page of missing features is shown with URL links explaining them.  Since 90% of those features were actually Windows features you go to add/remove features to install I don’t know why the Exchange installer doesn’t just offer to install them for me because it took some time to work out where in the multi level hierarchy of features each one was.  In addition serveral of the URLs brought up 404 pages on the Microsoft site refering to Exchange 2003 and that link not being available(!).  Anyway finally after a few hours of digging around, downloading libraries, installing features and restarting it agreed to install Exchange 2019 and I was done.

If you take one lesson from this it should be that the Microsoft solution to many problems seems to be “flatten and start over”.  For that reason I wouldn’t put Exchange on any machine you wouldn’t be happy to flatten and start over or replace.