WHAT NOT TO DO: Vista keeps killing Firefox: How to turn off Data Execution Prevention (DEP)
UPDATE: Doh! This killed my box, causing it to blue screen on boot. The solution was to boot with the install DVD, open a command line, and run bcdedit to turn DEP back on! I’m keeping it here as a warning for anyone who finds it.
I’ve bun running Firefox 3 betas for several weeks now. I started with beta 4 and am now on beta 5. My experience has been good overall, but one recurring issue is that Vista will occasionally shut Firefox down, claiming that it used memory inappropriately.
(Why do I feel like I’m loosing control of my PC? Will it one day shut down Word because it didn’t like my phrasing? 
I’m sure Vista is doing the "right thing" and Firefox is doing something wrong–it’s a beta after all–but it’s annoying nonetheless. Since I’m long since running without the protection of UAC (Vista: "You tried to say something bad about UAC. Confirm or Deny?") why not try to kill DEP.
My first attempt at turning off Data Execution Prevention was unsuccessful. While there is a method, accessible via the control panel, for allowing certain programs to be excepted from DEP, it doesn’t work for Firefox:
A few days and a few crashes later, I started Googling this issue again, this time turning up a way to disable DEP altogether:
I just did this–haven’t even done the manditory reboot yet–but I’ll try to remember to report back on whether it worked or not.