"Personal Computer (PC) Randomly Freezes"
Summary: one of the most common causes of annoying personal computer "freeze up" is the video board or driver.
Personal computer (PC) is fine and then suddenly, it is freezes and will not do anything.
Requires a reboot or even a system power off to get operational again.
There can be many causes of a system freeze but the most common cause is video hardwire and its associated driver.
Video circuitry and associated drivers are some of the most complex hardware and software inside a PC.
Steps you can take to ensure your system video is not the cause of your problem:
Make sure you have the latest drivers for you specific video hardware. Sometimes an update from the Microsoft Update website includes video driver updates for your specific video circuitry (built into many motherboards) or board but best to go to the manufacturer's website and download and install the drivers specific to your video.
If you have a separate video board, it is possible the video chip is getting too hot.
If there is a fan on the video chip, is it turning? If fan is not turning, most likely the fan has failed. A replacement fan can sometimes be hard to find depending on the make and age of the video board. Manufacturer or eBay as possible sources.
Is there adequate air circulation around the video board? Some high performance video boards can raise the internal temperature of a desktop to such a point that additional cooling fans must be added to the case to vent internal heat.
If you have a video board with or without a fan installed on top it is possible that the thermal paste between the video chip and the heat sink\fan needs renewal. This can be a do-it-yourself (DIY) if you are familiar with PC internals.
Finally, I have seen situations where the video circuitry on a desktop motherboard goes bad and a separate video board must be installed.
Ron Stultz.com - Shared Knowledge Home