It's nested in the control panel, in XP it's Game Controllers...but you can get to it by just running joy.cpl from the run line (search line in Win7 should pull it up). Highlight your controller in the list and click the "Properties" button. This should pull up a panel with a testing tab and a settings tab. Settings tab has a calibration wizard, and testing will show a button layout with icons that "light" when you press a button and such. This will show you what Windows is actually interpreting for your key presses.