I assume the computer you are referring to is using the Radeon 6770 graphics card. If so, download and install the latest graphics card driver here: AMD Graphics Drivers & Software
Also, check that your graphics card is clean and free of dust, pet hair, etc to rule out overheating. After you have completed both of those steps, check back here with the results. If it is still freezing up and the driver is crashing, we will look into it further.