With the proliferation of dual-core processors on consumer PCs, you may run into scenarios where some older applications either do not like your multi-processor environment and/or you wish to send an application to a specific processor (normally referred to as setting processor affinity).
To do so manually, you have to start the application, open the Task Manager window (Ctrl+Alt+Delete and click Task Manager), select the Processes tab and right click the process(application) you wish to manipulate.
A simplier way to do it is to use an application by the name of ImageCFG. ImageCFG allows you to launch an application from a batch file and set it to use a specific CPU without having to manually do it in Task Manager. http://www.robpol86.com/Pages/imagecfg.php.
After following the simple instructions (copy their two files to a couple of system directories), you can call the ImageCFG utility from a command line, tell it to open the app and set it to use a specific CPU.