This problem happens occasionally and I have been unable to pinpoint its cause or find a solution (other than rebooting). From time to time I start getting periodic CPU usage spikes, which temporarily freeze my computer (mouse unable to move) for a brief moment (a second or so). Opening the task manager, I get this:
The spikes are reported to rise up to 15-17% of total cpu capacity, but only on one of the cores. However, because the mouse (and everything else) freezes during such events, I believe they actually reach 100% of cpu usage, but the task manager doesn't update fast enough to register it.
The logical step after seeing these spikes was to check the process list, of course. I did so, and could not see any process significantly consuming cpu usage during the spikes. I selectively killed the processes one by one, seeing if the spikes stopped afterwards. In the end, I killed all processes not critical to Windows operation, but the spikes remained. Here's the list after doing that:
As you can see only system processes remain. So the problem is either with one of these, or an invisible process that the task manager cannot detect. (The process at the top is the Idle process, by the way).
Also, there's a possibility the spikes are related to failure of wireless connection. I just recently switched from normal to wireless internet connection, and I get occasional but complete losses of signal. Now, I'm not sure, but I have a feeling that the CPU spikes have appeared a minute or so before such disconnections.
Any ideas? I usually just reboot when it happens, which is not a terrible thing, but I'm curious as to what it could be.