System.exe psreturnprocessnonpagedpoolquota thread high CPU (100% of a core)?
I also experienced symptoms similar to you.I found a solution in my environment and will share it.
I investigated using Windows Performance Analyzer. As a result, I found that Wdf01000.sys! FxUsbPipeContinuousReader is using a lot of CPU.
When I disabled one USB Composite Device in Device Manager, the CPU usage rate dropped.Now CPU usage of System.exe is 0.1%.