To use VTune for system sampling, you will want to use Counter Monitor and Sampling together. Counter Monitor makes use of the Windows* Perfmon counters and then the sampling ties them together to allow view of source code. To do this follow these steps:
1. From the "Easy Start" dialog, choose New Project.
2. Select "Counter Monitor" Wizard and press "OK."
3. Check the "No Application to Launch" button and press "Next."
4. Check the bottom option,Typical Applicationand press "Next."
5. Choose the duration you want to run, then check the "Collect Sampling Data" checkbox and press "Finish."
The sampling run with then run with real-time counter data on the scree for as long as you entered. Upon completion of the run you will be presented with a dialog box to choose which run to view. Select "Counter Monitor Results."
Now you will see a graph display of the Perfmon counters, which you can then zoom in on and drill down to sampling data for the details during that particular time-period.
Press the Icon that looks like a graph (Select Range to Zoom/Drill Down) and then left-click and drag the region you want to view. Press the Magnifying Glass icon (Zoom) to zoom in on that view. When you are happy and ready to see the sampling data for that time-period, press the Drill Icon to "Drill Down" to the sampling view.
I hope that helps and enjoy VTune! :)