I think I confused Hardware and Software DEP in a recent post. The description of turning on Data Execution Prevention in the Performance option is Software DEP, as described by this Microsoft article.

Microsoft also has an article about turning on Hardware DEP, which, as Steve Gibson said in Security Now #78, can result in a system not booting because some 3rd party driver causes a DEP violation. So be careful when following the instructions, or wait for Steve’s DEPuty utility.