I have a client who currently has 2 separate forests. 1 contains 1 2000 DC, the other contains 1 2003 DC/File Server and 1 Exchange 2003 Server; they are trusted. What would be the BEST way to do an upgrade to 2008 on new hardware on both forests. Ideally I would have liked the 2000 forest to be a new parent in an existing forest but this is how I inherited the domain structure. The 2000 domain uses exchange off of the 2003 domain so each time I have to create a dummy user account in the 2003 AD, disable it, and then link it to an external account on the 2000 DC. I will getting new servers and converting everything to 2008 and setting up exchange 2007 too. Should I a) keep the existing forest structure and leave well enough alone or b) export the mailboxes to PSTs on 2000 domain user mailboxes, break the trust, and make the replacement 2008 server for the 2000 DC a new parent in an existing forest so I don't have to deal with trusts and what-not. I understand this is alot more labor from my end because I'd have to reconfigure each PC in that particular domain because of the new SSIDs and then copy over their old profiles. Does anyone have any other suggestions??