After build, the computer worked for several months. One morning it booted but Windows XP Pro began rapid "found new hardware" listing. When the motherboard was listed as found, I rebooted the computer. It made no sound, showed no video, and did not boot. When powered on, the computer remains on for several seconds and then cycles off and back on. It continues this on/off cycling behavior until the power button is turned off. Multiple attempts to boot the machine have produced the boot failure described above. I have checked the power pack, memory, DVD and hard drive. They work in another machine. I also cleaned the CPU fan and reseated it.
Based one the error message, it sounds like a video card failure assuming you have a separate video card and are not using the integrated motherboard video. This would somewhat explain the new hardware message. If the video card failed, it would load the driver for the integrated motherboard video. If this is the case, remove the video card and relocated the cable to the integrated video port.
If you were already using the integrated, then it may have failed, or the circuitry powering it. This would be a motherboard replacement.