You can manually set which core of the processor will be used by Windows 7 for multi core processors. Just like our previous tutorial, you need to launch the Windows Task Manager by hitting CTRL + SHIFT + ESC keys from your keyboard.
Now click the Processes tab and select the Program you want to change the settings. By default, all the cores are used by any program.
For lighter programs, you can free up one core. For this, right click on the desired program and click Set Affinity :
It will bring the window where you can select any core you want to allocate:
Select and click OK to save the option. Exit Task Manager.