Have you tried to set it at lower resolution or with lesser details? Maybe your computer can run older games at maximum details and resolution, but it cannot cope with Vanguard. Your issue is easily avoided if you set your graphics at lower level. On the other hand, if you do not want to do those things, you can buy new graphic card, new and faster processor and more RAM. Nevertheless, I think that setting graphics level at lower value will be smarter solution. In both cases, you will be able to play Vanguard. It is up to you.