Switch from Uniprocessor to Multiprocessor Support
From The Windows 2000 Development Team

As more and more systems crop up with the option of adding additional processors, you may want to optimize windows to take advantage of the additional horsepower. Switching from uniprocessor (UP) to multiprocessor (MP) support in Windows 2000 is simple when you use the Device Manager.

Here's how to do it in Windows 2000:

1. In Control Panel, open System, choose the Hardware tab, then click the Device Manager button.
2. Select the Computer node and expand it.
3. Double-click the first object listed below the computer node. On some systems, it is called "Standard PC". It might have a different name on your particular system.
4. Choose the Driver tab, and then click the Update Driver button.
5. On the Upgrade Device Driver Wizard, click the Next button, then select "Display a known list of drivers for this device so that I can choose a specific driver." Click the Next button.
6. On the Select Device Driver page, select "Show all hardware of this device class."
7. Select the HAL that matches your new configuration, multiprocessor or uniprocessor. Click the Next button. Check that the wizard is showing the configuration you want.
8. To install the driver, click the Next button.
9. To complete the wizard, click the Finish button.