Root cause for high CPU usage; which measurement to trust more: Windows Task Manager or Process Explorer?

Consider this Windows 8.1 machine (in-place upgrade from Windows 8) with differing reports on its CPU usage. The machine is idle, and has been for 3 days. There are no CPU intensive tasks running currently nor over the 3 day idle period.

Windows Task Manager is reporting CPU usage constantly at an incredibly high value (and increasing over time!) at around 75%.

Process Explorer from SysInternals reports that the CPU usage is much different at around 42%

  • How does Process Explorer report 42.14% usage, but its columns report Idle at 57%, with the sum of the other processes not even approaching 10%?

  • Which of these two values should I trust more, and why should it be trusted over the other measurement?

  • How can I actually determine which process is causing Task Manager to report its values?

These Proc Exp metrics were taken with Administrator privileges, and with option 'Show Details for All Processes'

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Solution 1:

I looked at the picture again and see that the sdclt.exe is highlighted in green. This means the process is started. I look at many xperf traces which also show this symptoms.

The solution to reduce the CPU usage is to stop the ConfigNotification task in the Windows Task Scheduler:

Task Scheduler - Microsoft - Windows - WindowsBackup

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Please, also contact Microsoft support and open a support case. They need a case to produce a fix for the backup task.