Put the power supply closer to the camera or try a bigger power unit. Double check firewall to ensure that it is not blocking the video stream port for the DVR. Next you have to custom set for the port in the exception list.
Check if the video card drivers are installed properly. (Click start-> My Computer (right click) -> Properties-> hardware Tab->Device Manager-> click Plus + sign next to Display Adapters. If it says “Standard Driver Display Adapter”, nail the issue by finding the Drivers of the Brand and Model of the Video Card. Have the ActiveX controls updated.
Check for the camera connection and power, make sure the cabling is okay. Check the settings and reboot the commercial video surveillance systems. Rebooting is one simple option which according to is the “Golden Rule” in IT troubleshooting, which would flush cache, settings to recalibrate, and connections to self revise. For rebooting, plug off the power supply, wait for few seconds and plug on again.
Also, check for IP address conflicts. Check if your camera is connecting to network using command “ping cameraIPaddress -t” .
Get it updated using latest firmware, and latest client software and reset it to factory default. Good Luck 