Data Execution Protection (DEP)

Data Execution Protection (DEP)
Be sure to answer question in complete sentences and full detail. Please provide research reference in APA style.
Viruses and other malware often exploit bugs known as buffer overflows in widely used software. One method of preventing these exploits in software running on current software version is Data Execution Prevention (DEP). Investigate buffer overflows and DEP. How does DEP prevent malicious attacks via buffer overflow? Is it always effective? Why might a user or administrator disable DEP?