How to solve high CPU usage when running Windows Virtual PC

When you run a virtual machine in Windows Virtual PC, you may experience high CPU usage in the guest operating system on certain hardware platforms, such as notebooks. Oddly however, when you examine Task Manager, no CPU usage issues are displayed in the host operating system. Keystrokes in the guest operating system are delayed and there is a definite lag in the response of the system.

The cause of this issue has been drilled down to the advanced power saving features that are built into the hardware of some notebooks, according to a latest report from Microsoft.

To resolve this issue, use one of the following methods:

Method 1

1. Shut down all the virtual machines that are running on the computer.
2. Start Notepad, and then click Open on the File menu.
3. In the Open dialog box, type %localappdata%\Microsoft\Windows Virtual PC\Options.xml in the File name box, and then click Open.
4. Replace
   <mm_timer_duration type="integer">10</mm_timer_duration>
   with
   <mm_timer_duration type="integer">1</mm_timer_duration>.
5. In Notepad, click Save on the File menu, and then close Notepad.
6. Open the Power Options item in Control Panel, and then make sure that the current power plan is set to Balanced or High Performance.
7. Start the virtual machine.

Method 2

This method enables Windows Virtual PC to fully use the processor and prevent the system from entering a low power state. For multicore systems, one core is used.

1. Shut down all the virtual machines that are running on the computer.
2. Start Notepad, and then click Open on the File menu.
3. In the Open dialog box, type %localappdata%\Microsoft\Windows Virtual PC\Options.xml in the File name box, and then click Open.
4. Under the <virtual_machines> tag, add the following line:
   <enable_idle_thread type="boolean">true</enable_idle_thread>
5. In Notepad, click Save on the File menu, and then close Notepad.
6. Open the Power Options item in Control Panel, and then make sure that the current power plan is set to Balanced or High Performance.
7. Start the virtual machine.

Method 3

1. Disable the Advanced Power Management options in the system’s BIOS.
2. Open the Power Options item in Control Panel, and then make sure that the current power plan is set to High Performance.