Originally Posted by Mike151Thomas
.. I play for between 1hr- 6hrs and then my computers freezes up, and the graphics get all messed up while I'm in game, and I am forced to shut my computer down by holding the button...
The messed up graphics are called artifacts, these are usually caused by heat or faulty video memory.
As Atomic Rooster has pointed out, check the video card fan is spinning, as it is a new card/pc I doubt dust is the cause which leaves case airflow.
What temperature is the card reaching at load?
What temperature is the CPU at load?
Which Forceware driver version are you running?
And as asked above by AR, what is your case fan configuration?