During a transition from Exchange Server 2007 to Exchange Server 2010 you may encounter an error removing a Public Folder Database from the Exchange 2007 server.

The error message tells you that the “Object is read only because it was created by a future version of Exchange”.

[PS] C:\>Remove-PublicFolderDatabase "EXCH07\Public Folder Database"

Confirm
Are you sure you want to perform this action?
Removing Public Folder Database "EXCH07\Public Folder Database".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help
(default is "Y"):y
Remove-PublicFolderDatabase : Object is read only because it was created by a f
uture version of Exchange: 0.10 (14.0.100.0). Current supported version is 0.1
(8.0.535.0).
At line:1 char:28
+ Remove-PublicFolderDatabase  <<<< "EXCH07\Public Folder Database"

The solution is to use the Exchange Server 2010 Management Shell to remove the Public Folder Database. From an Exchange Server 2010 server run the following command to retrieve the identity of the Public Folder Database you wish to remove.

[PS] C:\>Get-PublicFolderDatabase -Server EXCH07 | fl name, identity

Name     : Public Folder Database
Identity : EXCH07\Second Storage Group\Public Folder Database

Then run this command to remove the Public Folder Database, using the Identity that was retrieved in the previous command.

[PS] C:\>Remove-PublicFolderDatabase "EXCH07\Second Storage Group\Public Folder Database"

Confirm
Are you sure you want to perform this action?
Removing public folder database "EXCH07\Second Storage Group\Public Folder Database".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [?] Help (default is "Y"): y
WARNING: The specified database has been removed. You must remove the database file located in E:\Data\SG2\Public
Folder Database.edb from your computer manually if it exists. Specified database: Public Folder Database

The Public Folder Database is now removed from the Exchange 2007 server.