First, find the 'Run' function in the Start menu and open it. Then, type 'msconfig' in the window. Next, a settings window will pop up. Find the 'Boot' tab and select 'Advanced options...'. Another settings window will appear. Check 'Number of processors' and select according to your computer's configuration from the drop-down menu. Nowadays, dual-core processors are quite common, but there are also 4-core, 8-core, etc. After confirming the selection, restart your computer for the changes to take effect.