I have installed to my computer Autodesk softwares: Inventor 2011, AutoCAD mechanical, but none of them are running. I'd like to start the program, appears the "sandgalss", and in taskmanager Inventor.exe, but after few seconds nothing happens, Inventor.exe desappear from Task Manager. I tried to repair, but hasnt worked, reinstall also! What may be the problem that causes this? Something missing from Win 7?