* Sometimes it can happened because of incapable power supply. But at your configuration it is looking very enough. But you can control it anyway.
* It can be also about your graphic card. Use ATI graphic card with this configuration.
* Control your DirectX edition ( above Directx9 )
* All devices drivers have to be setup before u setup dvr card.
* Dont use graphical programs at your pc ( like AutoCad, Catia ). Actually you have to use that pc only for camera recording, it is best solution.
If problem still going on after u do that all. Problem causing by your motherboard.