Microsoft File Server Migration Toolkit

This wizard will help you migrate files between file servers and is even compatible with Distributed File System (DFS). It will keep all of your shares permissions and file permissions in tact.

Supported Operating Systems: Windows Server 2003 R2 (32-Bit x86); Windows Server 2003 Service Pack 2; Windows Server 2008; Windows Server 2008 R2

http://www.microsoft.com/downloads/details.aspx?FamilyID=d00e3eae-930a-42b0-b595-66f462f5d87b&displaylang=en