Why does a dual-core CPU appear as a single core in Task Manager?

Friends recently equipped with a dual-core computer, so that the installed staff installed XP system directly after the home, the results inadvertently open Task Manager, found that the CPU use records only showed a core, suddenly panic, thought to buy a fake.

Small series brought over to check, found in the Device Manager does have two core, why the task Manager in a core?

Look again, the original Task Manager CPU usage record is set up for "All CPU a chart", it is really make people laugh and cry, it is estimated that the installed staff lazy with Ghost to his installed pirated Windows XP, only to appear such a mistake.

The problem is solved by manually changing all CPU one chart to one chart per CPU in the CPU record of the View tab in Task Manager.