computer keeps getting error and shutting down

I just downloaded Vista, and now when I go to certain sites, such as pogo.com, my computer gets this black screen flashing on before my computer shuts down telling me it has to shut down or damage my computer. There is a bunch more stuff, but it flashes so quickly, I cannot read it. My computer restarts, but will ask me if I want to start in safe mode, or regular mode. HELLLLLPPPP!!!