Manage Windows Server 2003 Active Directory Tree

Our company has three separate Windows Server 2003 trees spanning three states. We recently used a Multi-Protocol Label Switched Virtual Private Network (MPLS VPN) tunnel to bring two remote sites to our corporate site. My ultimate goal is to manage the network like a forest and use two remote sites as a subdomain of the company. I know that it's easy to do this by deleting the Active Directory on both sites and then joining the company's domain as a subdomain, but this still requires re-establishing the user account and accessing all the machines to re-add them to the new one. In the domain. I know there will be other methods, please let me know, thank you.

I would suggest that you take a look at the Active Directory Migration Tool, which can be downloaded for free at a subsequent URL: http://www.microsoft.com/downloads/details.aspx? FamilyID=788975b1-5849-4707-9817-8c9773c25c6c&DisplayLang=en.

This tool will allow you to re-construct or consolidate the Active Directory tree you describe, including migrating computer accounts and user account passwords. There are of course third-party tools from NetIQ and Quest.