Uninstalling Exchange errors stating Folder Replicas exist
When try to uninstall exchange 2007 get error
“Uninstall cannot continue. Database “Public Folder Database”: The public folder database “SERVER\Second Storage Group\Public Folder Database” contains folder replicas…
Solution:
Run the Get-PublicFolderStatistics cmdlet using the Exchange Management Shell and check the output. If the folders listed are of no use then you can pipe this command with Remove-PublicFolder
Get-PublicFolderStatistics | Remove-PublicFolder
Once done, confirm there is no folders or no results by running same Get-PublicFolderStatistics cmdlet
Refer below article for further clarification
Clarifying the public folder store removal on Exchange Server 2007
http://blogs.technet.com/b/exchange/archive/2007/11/13/3404348.aspx