Download the latest Nvidia display card driver and
Driver Sweeper, then restart the computer and enter safe mode, use Driver Sweeper to remove Nvidia drivers, after that restart again and enter safe mode, install the new driver.
If the above method doesn't solve your problem, I recommend you to find some professionals to check both of the hardwares and softwares in the computer (like vLan shop ;) )
I personally think these problems are caused by some hardware failure.