Hi!
I have an issue with installing Exchange 2010 in an environment where 2013 was previously active(or might it be still active). Now first, this is a lab setup, so if it comes down it it, I'm just going destroy the domain and start fresh but I'd like to understand where I messed up.
Basically, I joined a Windows Server 2012 to my domain and installed Exchange 2013. That part went well but unfortunately, I lack the RAM to run both the mailbox and the client access role. Since I wanted to actually use the mail server, I figured I'd go back to Exchange 2010 which seems to be slightly less resource intensive.
Here is where I probably messed up:
1) I joined a new 2008r2 VM to my domain
2) I tried to install 2010 on that VM but the installation failed with the error message "the exchange organisation does not support this exchange version" or something similar. The original message was in French and a direct translation is awkward.
3) I realized that the AD might have been modified by the Exchange 2013 install and followed the instruction at the link in order to remove all the bits and pieces. I also deleted the Exchange 2013 computer from the AD.
www. markcc.me.uk/blog/files/DangerWillRobinson.html
4) That went well but the install still fails with the same error message mentioned at (2).
Now, what should I try?
I can
-Reboot the 2013 Exchange machine and rejoin the domain. Then, I can try to properly uninstall the Exchange 2013 component.
-Scrape whatever pieces are left directly on the 2008r2 DC and try to install Exchange 2010 again.
Or nuke everything from orbit, de-promote my DC and start fresh.
I appreciate any information on the subject.