Quote from tradezorro:
I've seen this with desktop computers and has typically been due to a faulty/floating ground. When you plug in the USB connector it shorts against the case and this reboots the system. (Laptops don't usually have this problem as they typically have plastic surrounding the USB ports.) I've typically seen this with the USB ports on the front of machines so you can try by carefully plugging into the USB ports on the back of the machine, the ports attached directly to the motherboard. Or better, use a USB extender cable to plug in the back of the motherboard and then, assuming no problems, carefully plug in the camera into the extender cable so as not to wiggle the computer side.