I've tracked a problem that only began since a recent clean install of the OS, in which the mouse cursor intermittently becomes erratic. When this does happen, the CPU becomes abnormally active, with spikes to about 30%, with the last 3 cores out of 6 going as high as 75-80%. The Performance Monitor shows that the S. I.s and DPCs are what are causing the activity, but of course doesn't explain why they are so active or what is causing it. Previously, I would move the mouse receiver (Logitech Unifying) to a different USB slot, and and it would calm down for a while, but eventually starts acting the same. I do not know for certain if the problem is with the mouse, the USB ports in use (USB 3.0), or with something in the OS itself or even some other hardware that is conflicting with it. Any idea of how to pinpoint the problem?