Monitoring CPU and Memory usage

[nimsaw]

How do i monitor my memory and CPU usage when the anti virus scanning is on in the background. Resource Monitor keeps changing every moment. Unlike Norton 360 not all security suites come with a Performance monitor. Is there any software utility that can give me the memory usage (MB) and CPU usage (%age) from the moment i start the AV scan to the moment i end it. I just want to monitor the scanner Process. Please help