Hard crashes caused by steam games

Hi community,

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.

Any advice is appreciated

If you need more info ask me, but i run avast antivirus as well as windows 7 64bit

UPDATE: I flashed the bios from f9 to f12

now when i open CS GO the game itself crashes and i am brought back to the desktop, instead of hard crashing my system.

Im open to new ideas, ill keep looking through other forums in the meantime