I am needing some guidance on the best approach for our migration. We currently have SBS 2003 running exhange 2003, Domain, and DNS. We also have a 2008 standard server with files and a database. Our corporate office has approved an upgrade and wants to virtualize using VMware 5.1 or 5.5 and 2012 Standard (single server). We are supposed to migrate the domain controller and dns to 1 VM, 2003 to 2013 using a 2nd VM, and the file share and database to a 3rd VM, a 4th VM could split the files and database or be used for future needs. I have already gotten pricing for the hardware and software to support these 4 VMs. My question is, What is the best way to approach this to have little down time. I know it is critical we do this in a particular order, and I am also aware a migration from 2003 to 2013 directly is not possible. Just looking for advice and feedback. Thank you for any advice you can lend.