DEP on EXPLORER.EXE

It has been plagued the computer for several years, the strange thing is that we cannot predict on what windows installation this Data Execution Prevention on Windows Explorer happened. some pop up some don’t.
Firstly we tough that is because we didn’t update the windows, so we do, but the thing happened again.
so curious we browse for information in microsoft (http://windows.microsoft.com/en-US/windows-vista/Data-Execution-Prevention-frequently-asked-questions)
here is what they said:
” DEP is a security feature that can help prevent damage to your computer from viruses and other security threats. DEP can help protect your computer by monitoring 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 ” Continue reading