While running Windows 8.1, CPU usage is 180% in Activity Monitor:
At the same time Windows Module Installer Worker service is overloaded in Task Manager (click Start -> enter “task manager” into Search field -> click on View running processes with Task Manager -> Processes tab > sort by CPU):
In Windows 8 or 8.1 virtual machines sometimes CPU fan run very fast and make noise because Windows Module Installer Worker service occupies CPU more than 50%.
Change Windows update into manual mode:
- Open services.msc:
- Search "Windows module installer".
- Double click the "Windows module installer", and make it manual (right click on service -> choose Properties -> Startup type: manual). It is usually set Automatic.
- Search "Windows update".
- Double click the "Windows update", and make it manual.
- Open Control panel (right click at the lower left of the screen at the Windows logo. and then you can see control panel menu).
- Click "Windows update"
- In left you can see "Change settings".
- Change the setting into "Check for updates but let me choose whether to download and install them". It is usually set automatic.
- Reboot Windows virtual machine.
Important: Because Windows update is set manual, you must check regularly (weekly or monthly) Windows update by yourself.