Laptop keeps shutting off ?

ok it seems like i have narrowed it down , my laptop runs fine when i am using it for other uses but once i plug my ethernet cable into my laptop and start to play xbox live after a while of playing on xbox live (about ten minutes) my laptop will shut off and all these words will come up ( i dont really remeber what the words are cus it comes off and on so fast but i do remeber it asking me has this happened before)and then the computer restarts and has to load up everything again and it says improper shut down also from a personal note this is really pissing me off cus i just bought this laptop with my employee discount and i dont want this xbox live connection screwing up my freakin laptop