Question : Problem: How to see the loading of each individual core of dual core (intel core2duo) processors?

I am using a system with Intel Core2Duo processor (E6400 / 2.13 GHz / 1066 MHz FSB).
I have got a software written for it running on Windows XP Embedded. Now I want to test whether the software takes the advantage of multi core processors by utilizing them equally.
How to go about this? Are there any softwares which can provide the utilization of each individual core?
The task manager itself shows two processors but is it trustable? Another option was to measure the core temperatures. If the two temperatures are same, is it that both are utilized to the same extent? but I object this one as both the cores are on the same die, the temperatures would be almost identical.

Answer : Problem: How to see the loading of each individual core of dual core (intel core2duo) processors?

I think using up.time software for 15 days will be fine Here is the trial link:
http://www.uptimesoftware.com/register_standard.php