When I click the left mouse or lower trackball button, nothing happens

Check the following:

• Make sure that the pointing device is plugged into the computer.
• Make sure that IntelliPoint is installed correctly.
• Try using the right mouse button or upper trackball button to see if it has been set as the primary button.
• Use the keyboard to set the left mouse or lower trackball button as your primary button:
  1. Press the Windows logo key (), press the UP ARROW key to select Settings, press the RIGHT ARROW key to select Control Panel, and then press ENTER.
  2. Press the DOWN ARROW key to select the Mouse icon, and then press ENTER.
  3. Press SHIFT+TAB to select Activities, then press the right arrow to select Buttons.
  4. Press TAB to Select your mouse or trackball under Device, and then press the UP or DOWN ARROW to select your device.
  5. Press TAB to select the primary button assignment—for example, Left Button under Button Assignment—and then press the UP or DOWN ARROW to select Click.
  6. Press TAB to select OK, and then press Enter.