Certain Intel processors implement the Execute Disable Bit functionality, thus preventing certain classes of malicious “buffer overflow“ attacks -- when combined with a supported operating system. Although not a new technology, Intel is aggresively providing end-to-end workstations and servers this year.

Execute Disable Bit currently requires one of the following operating systems to support it:

• Microsoft Windows Server 2003 with Service Pack 1
• Microsoft Windows XP with Service Pack 2

Read Intel's article here.