1. Load the virtual machine and allow Windows to boot. Log in using an account that has Administrative privileges.
2. Press the Windows logo and 'R' keys simultaneously to display the Windows 'Run' dialog box on the virtual machine. Type 'devmgmt.msc' without quotation marks in the dialog box and press 'Enter.'

3. Double click the 'Computer' heading in the Device Manager to expand the category. This reveals the HAL currently installed, e.g. 'ACPI Uniprocessor PC.'
4. Right click the HAL displayed and click 'Properties.'
5. Click the 'Driver' tab, then click the 'Update Driver' button.
6. Click 'Install from a list or specific location,' then click 'Next.'
7. Click 'Don't search, I will choose the driver to install,' then click 'Next.'
8. Select the HAL that you want to use (e.g. 'ACPI Multiprocessor PC') and click 'Next.' The drivers are installed.
9. Close every window, then click 'Yes' when prompted to restart the operating system on the virtual machine. Windows restarts with the correct HAL for a multiprocessor computer.