Did you run the DISM part too as it's not exactly the same as running scannow twice?
In any case, your CPU normally has 4 cores which carry 2 processors each making an eight core chip. Task Manager is reporting that two of the cores aren't running or are turned off.
Device manager I note is showing an eight core processor.
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I've seen this happen with a corrupted operating system which is why I wanted you to run the scans.
Open the run app, type msconfig, click ok and from the revealed box look for 'Boot' followed by advanced options.
Just see if it looks the same as mine:
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Please go into the bios and click the optimised defaults key.
Once you've done that go back into the bios and check to see if all cores are enabled.
If all the cores are enabled in the bios but not in windows then it could down to os corruption and ideally you need to install a fresh copy of Windows 10. This has to be a clean install meaning no upgrade which to be honest is an awful process and i wish Microsoft would find a better way of doing things.
If you need to obtain the Windows 10 iso in order to create a disk or usb then use Microsofts media creation tool:
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