|"I realized in the display devices it says dedicated memory = 0"|
And that's what it should say. The GMA950 has no memory of it's own...it uses the system memory. That's why it lists shared memory as 224MB. If anything, you should lower it so that the OS has more RAM available. Vista performs best with 1GB or more. Since the GMA950 is taking 224MB, there's only 800MB left for the OS.
If the system's shutting down, it's probably overheating.