So - in summary, two completely different sticks from different manufacturers are now both spiking like crazy in the Window's calibration screen, regardless of which USB port you plug them into?
If you haven't done so already, make SURE that you've disconnected every other USB device. The most likely reason I can think of that something like what you've described would happen is if the USB voltage is fluctuating - most joysticks require an absolutely stable USB voltage in order to provide a steady output. That could be a device that is is intermittantly drawing too much power (defective, or you've overloaded it), or the motherboard or power supply isn't supplying steady power.
Otherwise, I'm not sure where else to go with it.
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