Random freezes and BSODs dxgkrnl.sys - nvlddmkm.sys - dxgmms1.sys

the bugcheck just indicates that the graphics hardware and driver did not respond to windows in a timely manner. This is very common with overclocked hardware, the only thing you can do is reduce the overclock and reduce the demands on the driver/hardware.

you might find that going to windows control panel, device manager, find your graphics driver high definition audio support and disable it if you are not using it might help.
it reduces the load on the gpu and gives the GPU a bit less work to do. Many people don't even have speakers in their monitors that are connected via the HDMI or displayport so they don't need to have it enabled.

for a nvidia system you might also turn off the streaming functions until you actual use it. It depend on your ethernet drivers and if your drivers are out of date the errors tend to mess up the nvida drivers causing the driver to not respond in a timely manner. then windows attempts to reset the driver/graphic card and things go down hill from there.

some motherboards also provide a 3% overclock on the GPU via the motherboard BIOS
turn this off if you have a overclocked GPU or run any overclocking software.
nothing more screwy to mess with than a BIOS overclocking a hardware overclocked GPU that is also being overclocked with software.