How does Data Execution Prevention work?
Data Execution Prevention aims to protect your computer by making it harder for hackers to silently execute their programs in your PC. As Windows runs, its Virtual Memory Manager maps addresses in RAM to locations on the hard disk (in the pagefile or swapfile). At the same time, hardware DEP inserts a special bit into the disk version of an address, marking it as non-executable. If a hacker program attempts to write code to such a location and then execute it, a DEP-enabled processor detects the exploit and registers an error. If so, Windows can shut down the problem application or, if the hacked code is in an area used by Windows, halt a portion of the operating system itself. Windows XP Service Pack 2 (SP2) has a software-only version of DEP, which is not as effective as the hardware version. Fortunately, Vista provides support for both software DEP and hardware DEP. In either case, you’ll want to turn on those DEP settings that you can benefit from. Vista users should read on, while
