I have been asked to move current Exchange 2010 setup to a new and much more powerful server, decommission the old one from the domain. Started of by setting up and update the new server, joined the domain, installed Exchange 2010 prerequisites and then I installed Exchange 2010, reboot and updated again…
Then I did a local mailbox move request for all the mailboxes to the new server and waited for the sync to finish, did some DNS changes and connected via Outlook anywhere by a local computer to exchange and saw that it was connect to the new server = beautiful… update done and client connect to the new server 
Then I was going to uninstall Exchange 2010 on the old server and so I went to the control panel and few seconds in the uninstall process I got an error about Public Folders Replicas on the old server, a bit odd cause I didn’t know they had Public Folders but then again OAB uses Public Folder so I moved OAB to the new server and tried again but no luck. I remember when Exchange 2010 went RTM that I had problems like this while moving a company from Exchange 2007 to Exchange 2010 and back then I found the answer online somewhere.
I search trough my favorites, my how-to´s, Google and Bing but I didn’t find it but I remember that I used good old ADSI Edit to delete entry’s relating to Public Folders from Active Directory. I found two entries and first I delete one, tried again = didn’t work so I deleted the second one, tried to uninstall again and it worked this time.
Info about ADSI Edit : http://technet.microsoft.com/en-us/library/cc773354(WS.10).aspx
Download here : http://www.lappari.com/wp-content/uploads/2011/02/adsi.rar
DISCLAIMER !!!!
Posting “AS IS” with no warranties 
The first entry I delete is here (delete everything in the right hand pane)
CN=Configuration
CN=Services
CN=Microsoft Exchange
CN=<domain>
CN=Administrative Groups
CN=Exchange Administrative Group
CN=Folder Hierarchies
The second entry I delete is here (delete everything in the right hand pane)
CN=Configuration
CN=Services
CN=Microsoft Exchange
CN=<domain>
CN=Administrative Groups
CN=Exchange Administrative Group
CN=Servers
CN=<old server name>
CN=InformationStore
CN=First Storage Group
Then I re-ran Exchange 2010 uninstaller from add-remove programs in Control Panel and it worked
I am so glad I still remember the old message I found about then online although I didn’t find it now but if I find it again I will post it here… All credit goes to…. that guy…
2 athugasemdir
Hi Lappari, great write really.
I have similar issue. Some guys installed clean exchange 2010, with public folders, databases and so on. Than they deleted the whole server (because they didn’t know ho to uninstall it correctly).
Then they installed new exchange 2010 server, but ofcourse, there are traces of old server (mailbox, public folders and so on).
Do you think I could try deleting public folder/replicas using this method you show here ?
I succeded to delete one mailbox, but will need obviosly to use ADSIedit for publicfolders…
Thanks
Hi Somebody here 🙂
First: Posting “AS IS” with no warranties 🙂
Only way I know is to use ADSIedit to get rid of old Exchange servers and to delete all public folders so I say yes… I would do it myself…
You should first take a full backup of the new server and in ADSIedit you should be safe to delete every entry pointing to the old server.
Please let my know how it goes
Lappari