HY, Install the new server and in the setup take join an existing site, then you give the name of the other Exchange 5.5 Server then after the installation you can move all the mailboxes to the new server, in the Exchange Admin Menu under Tools - Move Mailboxes or you open each mailbox and give the name of the new server. After that you can delete in the admin tool the old Exchange 5.5 Server. Hope that will help you! BYE, SASCHA