This was really driving me nuts and almost caused me to completely switch to Chrome which I use from time to time. Here’s how I resolved the problem. As soon as I would launch IE 8, the Data Execution Prevention (DEP) dialogue box would pop up. I would hit OK and then it would shut down IE 8. I tried disabling DEP for Internet Explorer but this still happened at first about 50% and then almost 100% of the time. I even tried uninstalling the MSJVM. None of this helped.
I noticed that if I did not clear the DEP dialogue, I could move it out of the way and open another tab in IE8. I could also select Tools, Manage Add-Ons. I then disabled most of the add-ons (ones I didn’t really need or didn’t even know were there). That did the trick.
Hopefully this will help any other unfortunate souls out there with this very annoying problem.