Hmm, if I am not mistaken that is an error you get when you are not supplying enough voltage to the processor. Have you overclocked your processor at all? It could possibly also be the GPU, is that overclocked? It could really be either one because when you start running DOTA2 both your processor and your GPU are drawing more power.
Best way to test this is to uninstall your Nvidia drivers and remove your graphics card, and try running the game with the integrated graphics. Obviously you dont want to play it on the integrated, but if the game loads up just fine with no problem then the issue is with your graphics card. Test it out and let me know.