When you have a computer with a recent model CPU, chances are it’s a dual-core CPU. Both Intel & AMD have been producing dual core CPU’s for a few years now. By default, Windows Vista will only use a single core during boot-up. You can easily change this from the System Configuration utility:
-1-In Vista’s Start Search type msconfig & hit the [Enter] key on your keyboard
-2-Once System Configuration has started, select the Boot tab and click the Advanced Options button
3. In the BOOT Advanced Options dialog, check the “Number of processors” check box, and choose 2 (or 4 if you have quad core) for the number of processors.
4. Click OK twice. Done and done.