DEP is technologies included into Windows XP SP2 and avoid code from being run in particular regions of memory that are for storage. Using this you can avoid all types of attacks that would be run freely on your machine. DEP comes in two types, hardware-enforced and software-enforced.

Many users will never to be concerned about DEP because it works in the background and generally only protects Windows system binaries or programs that “opt-in”. Though, if DEP is turned on for all programs, it can cause problems with some certain programs.