masingh, assuming Toshiba's help and support feature that comes with Windows XP (and assuming you have XP) is similar to that of HP (the one I am using right now), you can find your notebook's serial number by following these steps: 1. Click "Start" button 2. Click "All Programs" 3. Click "Help and Support" You will see the notebook's serial number along with few other information about your notebook on the top left pane of the dialog box. Hope this helps. Let me know! :)