Data Execution Prevention (DEP) is a set of hardware and software technologies that perform additional checks on memory to help prevent malicious code from running on a system. In Microsoft Windows XP Service Pack 2 (SP2) and Microsoft Windows XP Tablet PC Edition 2005, DEP is enforced by hardware and by software.
The primary benefit of DEP is that it helps prevent code execution from data pages, such as the default heap pages, various stack pages, and memory pool pages. Typically, code is not executed from the default heap and the stack. Hardware-enforced DEP detects code that is running from these locations and raises an exception when execution occurs. If the exception is unhandled, the process will be stopped. Execution of code from protected memory in kernel mode causes a Stop error.
DEP can help block a class of security intrusions. Specifically, DEP can help block a malicious program in which a virus or other type of attack has injected a process with additional code and then tries to run the injected code. On a system with DEP, execution of the injected code causes an exception. Software-enforced DEP can help block programs that take advantage of exception-handling mechanisms in Windows.
However if a program is failing and you want to disable DEP, or if you have a new CPU that supports DEP you might want to always enable it. You can do it in two ways:
The first way is via the system properties.
- Click Winkey+Break
- Go to the Advanced tab
- Click the Performance Settings button
- Click Data Execution Prevention tab
- Use one of the following procedures: Click Turn on DEP for essential Windows programs and services only to select the OptIn policy. or Click Turn on DEP for all programs and services except those I select to select the OptOut policy, and then click Add to add the programs that you do not want to use the DEP feature.
- Click OK two times.
The second way is to update the boot.ini file
To configure DEP to switch to the AlwaysOn policy by using the Boot.ini file, follow these steps: (more…)