Obvious question, but have you just tried uninstalling Daz, and if you have Win XP going back to a System Restore point before you installed the DirectX update? could be worth trying. If you're not on XP, then do a whatever-it's-called boot-up where you can load one thing after another and see where you have the problem. I'd exhaust all avenues before bringing it into a repair shop, because my experience has been that they just want to re-format (which I could have bloody well done myself without having to pay them!)