Data Execution Prevention: frequently asked questions

Here are answers to some common questions about Data Execution Prevention (DEP).

Show contentHide content What is DEP?
DEP is a security feature that can help prevent damage to your computer from viruses and other security threats. DEP monitors programs to make sure they use system memory, safely. If a program tries running (also known as executing) code from memory in an incorrect way, DEP closes the program. DEP automatically monitors essential Windows programs and services, but you can increase your protection by having DEP monitor all programs. For more information, see Change Data Execution Prevention settings.

Show contentHide content Is it safe to run a program again if DEP has closed it?
Yes, but only if you leave DEP turned on for that program so that Windows can continue to detect attempts to run code from protected memory locations and help prevent attacks.

Show contentHide content If DEP keeps closing the same program, is my computer under attack?
If you are using the recommended security settings and your antivirus software did not detect a threat, your computer is probably not under attack. In this case, the program might not run correctly when DEP is turned on. Check for a DEP-compatible version of the program or an update from the software publisher before you change any DEP settings.

Show contentHide content How can I prevent DEP from closing a program I trust?
First, see if a DEP-compatible version of the program is available by visiting the software publisher's website. If the publisher has not released an updated, DEP-compatible version of the program, you can turn off DEP for the program that was closed. You will be able to use the program, but it might be vulnerable to an attack that could spread to your other programs and files.

To turn off DEP for a program, see Change Data Execution Prevention settings. If you choose to turn off DEP for a program, it is a good idea to check frequently for an updated version of the program and, after you update it, to turn on DEP again.

Show contentHide content What should I do if DEP is closing a program that’s part of Windows, such as svchost.exe or explorer.exe?
The svchost.exe and explorer.exe programs are parts of the Windows operating system. If DEP closes them or other Windows services, the cause could be smaller programs, such as extensions, that are created by other software publishers and that operate inside Windows. If you have recently installed a program and notice DEP closing Windows programs, check with the software publisher to see if there is an updated, DEP-compatible version available, or try uninstalling the program.

Show contentHide content If my DEP settings indicate that my computer’s processor does not support hardware-based DEP, am I still protected?
Yes. DEP is a software-based feature of Windows. Some computer processors also provide hardware-based DEP under various names. These processors use hardware technology to prevent programs from running code in protected memory locations. If your processor does not support hardware-based DEP, Windows will use software-based DEP to help protect your computer.