I don't know what you've tried so far except runonce and the user's Autodesk folder reset, but I would also suggest to remove all external addons/plugins/workgroup (not provided with Soft), and see if you experience the same crash. If you don't, then you know your problem lies somewhere in there. Having a virgin Autodesk directory would be a good thing too, I've seen crashes with custom UI Layout sometimes, even if they were not in use.
You could also try any equivalent of strace (linux) on windows ... I think there's one. Might tell you at which point it's crashing.
