I've used LDD throughout the years. A while ago I've been unable to make it work on my main PC. I'm using a Radeon HD 4870 X2 and Windows 7. When I open LDD 4.0 it will crash the video display. The error I get is "Display Driver has stopped responding and has recovered" However, I don't know what I did, but I uninstalled LDD then downloaded LDD 4 and reinstalled it. It worked once, then the next time I opened it it failed to work. I can only close LDD4 through the task manager via End Process. My PC is kept up to date constantly especially the video card. I've tried disabling the advanced graphics in the .ini file. I have Lego Universe. I even enabled Universe mode before I installed Lego Universe. I tried turning off universe mode. Other than use another computer, what could I do to make it work on this one?