I hope someone can help me. This started about a week ago. I have a Dell Inspiron 9300. Anytime I close a browser window, I get the message:

Data Execution Prevention - Microsoft Windows
To help protect your computer, Windows has closed this program.

Then after I close the message, I get the option to send or not an error report.

It is very annoying to have to close these messages each time. I have read old threads regarding similar but none seem exactly like mine due to that I am the one closing the window.

Which version of windows?
Which browser (and version)?
Have you installed any plugins recently?

You can either turn it off for non-essential windows programs, or add an exception for your browser.

But it shouldn't really be executing data as code to begin with.

I am so sorry I left out that info.

Windows XP media center
I can't think of anything new that I have added.

I could disable it, but is that bad?

Again, thank you for your help.

Have you sent a report?
Sometimes, it gives you a link to more information (which may be useful).

Are you up to date with Microsoft updates? Did the problem start with the last update?

I would be very cautious about turning DEP off for the browser. IE8 by itself should have no good reason for triggering DEP errors.

What about your AV software, is that up to date? Have you done a complete scan?

Also visit this forum down the hall.
Read some threads on how to download and run "Malwarebytes Antimalware" and "HijackThis". Start a new thread and post logs if you're unsure.