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 to help prevent code execution from data 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. Software-enforced DEP can help prevent malicious code from taking advantage of exception-handling mechanisms in Windows.
Quoted from http://support.microsoft.com/kb/875352
Sometimes DEP block some program to run. To Add exception to DEP, you can go to:
- Klik Start, right click on My Computer and choose Properties.
- Go to Advanced tab and click Settings in Performance block.
- Go to Data Execution Prevention tab, click Add to add exception to specific program to run.
If you want to completely turn DEP off, you can do this:
- Explore C:\
- Click Tools >> Folder Option >> Views
- Uncheck Hide Protected operating system files (Recommended) and Hide extensions for known file types
- Click Apply >> OK.
- Edit Boot.ini file.
- Modify the /noexecute= to /noexecute=alwaysoff to disasble DEP entirely
- Save and reboot your computer.