Question : Exchange 2007 Installation

I'm preparing to install Exchange 2007 for the second time on my Windows 2003 environment.  A while back I had configured Exchange 2003 but ended up removing this server from my environment without uninstalling Exchange 2003 or removing the server from AD.  In order to start fresh, I want to delete any instances of Exchange 2003 and Exchange 2007 from my environment.  I noticed when using the ADSI Edit utility, I see many entries with
CN=ms-Exch under the Schema Tab.  I have already delete Exchange instances from the Domain Tab.  Can I delete all of the entries that have CN=ms-Exch next to them?  Are they all part of either an old installation of Exchange 2003 or Exchange 2007?  Please advise.  Thank you.    

Answer : Exchange 2007 Installation

Never touch the Schema Partition :( :(

If you want to remove the server object from your environment do this
http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/Q_24833787.html

Also if there is some info about a Old DC not removed properly get a Metadata cleanup
http://support.microsoft.com/kb/216498