The hardware enforced Data Execution Prevention feature (DEP) in Windows XP SP2 and Windows Server 2003 SP1 and SP2 doesn't offer a reliable protection against buffer overflows in its default settings. Please click here to learn more about the benefits of using BufferShield instead of hardware DEP.
Microsoft's DEP software based approach does, opposed to the widespread believe of protecting from buffer overflows, explicitly protect from one specific exploit that occured one time only and is based on overwriting the pointer to the SEH Exception Handler.So giving this software based feature a similiar name as the hardware NX protection is confusing the customers globally. It is either a demonstration of technical incompetence or a demonstration of MIcrosoft's marketing powers. You decide. However, we have the strong suspicion that Microsoft might have been influenced to deliver this specific feature in this way.