lollaubla 0 Newbie Poster

It was working fine a few days ago. It's not down to the file types. It's saying something about Data Execution Prevention. I have turned off DEP via cmd I have uninstalled and reinstalled my codecs and I have no idea what to do next. Nothing I try is working, i don't even know what caused it one minute it was fine and the next it just stopped working. I get as far as trying to add a movie and thats it. Thanks