Hard Crashes Caused By Steam Games

Today, i have discovered that only certain games in my steam library causes crashes. However, when i google this problem, the only threads i see describe simple game crashes that merely take you back to the desktop. This does not compare to my crashes, which end up being a hard computer freeze, only curable by a click of the reset button on my tower..Note that i play Diablo 3, Battlefield 3, and SWTOR perfectly normal and as far as steam games go i can play the original Counter Strike, Skyrim, and a few other i believe.The only 2 games so far that i have had this same problem with is LOTR War in the North and recently i got the CS/GO beta and that crashes as well. Another characteristic of these crashes is that they occur on startup, As soon as the first image of the startup shows on my screen, I am given that circular ring as a cursor, then a second later it stops revolving and my entire pc is frozen and unresponsive. I tried running steam as an administrator, the only difference was that i had control of the mouse a few moments longer before it froze again, but this time it was an actual cursor.