Active Directory Migration Tool version 3.2
If you have ever tried to install the previous version of ADMT on Windows Server 2008 R2 you received an error message, right? Okay, now that is part of the past the new version supports Windows Server 2008 R2, finally!!! :)
The Active Directory Migration Tool version 3.2 (ADMT v3.2) simplifies the process of migrating objects and restructuring tasks in an Active Directory® Domain Service (AD DS) environment. You can use ADMT v3.2 to migrate users, groups, service accounts, and computers between AD DS domains in different forests (inter-forest migration) or between AD DS domains in the same forest (intra-forest migration). ADMT can also perform security translation (to migrate local user profiles) when performing inter-forest migrations.
Get it from here: http://www.microsoft.com/downloads/details.aspx?FamilyID=20c0db45-db16-4d10-99f2-539b7277ccdb&displayLang=en