Make sure that the voltage probes are properly connected to measure the voltage VC across the capacitor. (Does it matter which wire (red or black) is connected to which end of the C?) Make sure that the PASCO interface is powered on (the power button should be glowing blue light) Open PASCO (start -> All Programs -> PASCO scientific -> PASCO Capstone), and click on Hardware Setup in the upper left corner. You should see a picture of the PASCO interface box. Click on the part of the picture that corresponds to the channel A that you plugged your voltage probe into