How to Fix High CPU Usage / Memory Usage / Disk Usage (Service Host: Local Service) in Windows 10, 8.1, 8, 7

Before you try this method please try the above mentioned methods :

• sfc /scannow
• Dism /Online /Cleanup-Image /RestoreHealth
• Disable service "SuperFetch"

If you have tried all of them and still didn't get the issue fixed out then this is for you.

1. Identify if you are running the inbox AHCI driver (StorAHCI.sys):
   
   
   1. Open up your Computer Management by Win + R then put in devmgmt.msc and hit enter
   2. Under IDE ATA/ATAPI Controllers right-click on the AHCI controller node and select Properties. This node is usually called “Standard SATA AHCI Controller.”
   3. Navigate to the driver tab and click Driver Details.
   4. If you see “StorAHCI.sys” in the list, you are running the inbox driver.
   
   
   
2. Disable MSI for the controller in the registry:
   1. In the same properties window opened in step 1.2, navigate to the Details tab and select Device instance path from the Property drop-down menu. Note this path. 
   
   
   
   
   
   1. Open the registry editor by typing regedit in the previously opened command prompt.
   2. Navigate to: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\PCI\ <AHCI Controller>\Device Parameters\Interrupt Management\MessageSignaledInterruptProperties, where <AHCI Controller> refers to the device instance path you noted in step 2.1. 
   3. Change the value of the MSISupported key from “1” to “0”.
   1. If you don’t know which controller your boot device is attached to, repeat steps 2.1 through 2.4 for all AHCI controllers found under 1.2.
   
   
   
3. Reboot the machine.

It fixed the problem in my case see :

Hope this helps.

Credits to : Microsoft Support