The UAC (User Account Control) prompt in Windows Vista is a security tool to prevent unauthorized access to the system. The problem I find in the field is that there will always be a percentage of users who will click “continue” = (please allow this malicious code to run on my PC because I really don’t know any better). It may also be difficult to manage the security of a computer when it is accessed by multiple users, and you need a secure computer on your network or in the office. There is a solution to this problem. It is a fiddly, requires familiarity with the mouse and navigation in Vista, but if you want to lock down Vista and prevent malicious code from running DEP is your answer.Data Execution Prevention has been around since Windows Server 2003 and monitors the way programs use system memory. If the program attempts to access memory in an unsafe fashion, DEP closes it down. If the program has a valid ActiveX Control it should execute correctly. If it will not install or run and you know this program is safe you can add it to the DEP allowed list. The computer needs to be restarted after DEP changes. Not every program that is blocked by DEP is malicious or spyware but if DEP is monitoring the program it can detect attempts to execute code from protected memory areas, and help to mitigate the threat of attacks.If DEP closes the program you know is safe, try checking for a DEP capable version of the program or contact the vendor before changing DEP settings.To access DEP settings and add or remove programs from the allow list:

·         Go to start ·         Right click computer ·         Select properties ·         Select advanced system settings ·         Note the UAC prompt and continue ·         Select the advanced tab ·         Select the performance tab > settings ·         Select data execution prevention ·         DEP is turned on for essential Windows programs and services only by default – choose to turn on DEP for all programs ·         Restart the computer ·         If a new third party program does not run and is blocked by DEP specifically you can add it to the list by (A) turning off DEP, restart PC, install new program, turn on DEP and add the exe of the program to the DEP list, restart PC. We turn on DEP on request or for some security scenarios on our new computers. A program blocked by DEP does not always notify you. DEP is not for everyone but is highly effective if you need advanced security.