Tip: Assign a Program or Process to a Specific CPU running on Windows 7
If you have a dual-core or multiprocessor system, you can assign a process to a specific processor. But you can only do this after the process is already running. To do this, open the Task Manager and go to the Proc esses tab. Right-click the process you want to assign and choose Set Affinity. A dialog box will appear, letting you select the processor you want the process to use.
If all CPUs are selected, Windows will set the process affinity as it sees fit.