Exam 70-643 is designed to test your ability to create, maintain, protect, and recover networks running Windows Server 2008. Before taking this exam, you should make sure that you know how to install Windows Server 2008 and how to turn a workgroup deployment into a domain. You should also know how to backup and restore your domain controllers.
In addition to knowing the basics of setting up an Active Directory environment, make sure that you know how to configure and use the more common network services such as DNS and DHCP.
This exam also tests your ability to work with basic file and print services. Therefore, be sure that you know how to set up a DFS root and how to maintain disk quotas. You should also be able to configure the print services.
Keep in mind that these are just some of the main areas that you should focus on, not the full exam objectives. The official exam objectives are listed later in this exam profile.