'Modern Setup Host' High CPU Usage

Modern Setup Host and its related process name SetupHost.exe represent a vital Windows process that is invoked whenever a major update is being installed. It also is responsible for triggering Windows to check for and install newer updates. Another Modern Setup Host task is to assist in upgrading older Windows releases, mainly Windows 8 to Windows 10. 

Usually, Modern Setup Host runs in the background and users do not even notice its presence. However, the process can begin to exhibit abnormal behavior, where it takes up an exorbitant amount of CPU or Disk resources. As a result, the whole system could begin to run extremely slowly and freeze while individual applications could crash completely. Users encountering this issue have a few options they could try. 

Disable Suggestions, Application Control and Background Applications

1. Open 'Settings' by right-clicking the Start menu and choosing it from the available options. 
2. Open 'System.'
3. From the left pane, select 'Notifications & actions.'
4. Locate the 'Get tips, tricks, and suggestions as you use Windows' and disable it by unchecking the corresponding box. 
5. Go back to the main 'Settings' window.
6. Go to 'Personalization.'
7. Select 'Start' from the left pane.
8. Locate the 'Show suggestions occasionally in Start' option and set its toggle to Off.
9. Go back to the main 'Settings' window.
10. Open 'Update & security.'
11. Select 'Windows Security.'
12. Select 'App & browser control.'
13. In the new window, select 'Reputation-based protection settings.'
14. Toggle off the following option - Microsoft Defender SmartScreen for apps and files, Microsoft Edge, and Microsoft Store apps.
15. Close the 'Security' window and go back to the main 'Settings' window.
16. Go to 'Privacy.'
17. Select 'Background apps.'
18. Toggle off all apps that you deem as unnecessary.
19. Close the 'Settings' window.
20. Press the Windows key + R on your keyboard.
21. In the Run dialog box, type control.exe srchadmin.dll and click OK.
22. Click on 'Modify.'
23. Uncheck all options located in the top part of the window.
24. Click 'OK' and close the 'Indexing options' window.

Run a DISM Scan

1. Press the Windows + R keys on your keyboard.
2. In the Run dialog box, type cmd and press Ctrl+Shift+Enter on your keyboard to open an elevated Command Prompt window. 
3. In the Command Prompt window, first type the DISM /Online /Cleanup-Image /ScanHealth command and press Enter.
4. Then, type the DISM /Online /Cleanup-Image /RestoreHealth command and press Enter.
5. Wait for the process to finish, close Command Prompt, and restart the system.

Run an SFC scan

1. Open an elevated Command Prompt by following the first two steps of the DISM process.
2. Type sfc /scannow and press Enter.
3. Wait for the process to complete, close the window, and restart the system.

Clear the SoftwareDistribution Folder

1. Open an elevated Command Prompt by following the first two steps of the DISM scan process.
2. In the Command Prompt window, first type net stop wuauserv and press Enter to execute the command.
3. Now, type rd /s /q %systemroot%\SoftwareDistribution and press Enter once more.
4. Finally, type net start wuauserv and press Enter.
5. Close Command Prompt.