Make sure no other devices are connected to USB ports on the computer (except keyboard or mouse), then reinstall the driver with these steps:
1. Close the LeapFrog Connect Application.
2. Quit the monitor:
a. Press Ctl-Alt-Del on your keyboard
b. Select Task Manager
c. Select Processes
d. select Monitor.exe and end process
3. Connect the LeapPad, turn it on, and go to the Device Manager on the computer
a. Right click on My Computer and select "Manage" and select device manager OR click the Windows Start button, and type devmgmt.msc into the Search box.
4. In the device manager under the Universal Serial Bus Controllers you should see an item named USB Mass Storage Device.
5. Double click on this device, go to the drivers tab and click uninstall.
6. In the device manager under Disk Drives, you should see an item named LeapFrog Explorer USB device.
7. Right click on this device and click uninstall.
8. Disconnect the LeapPad
9. Launch LeapFrog Connect and allow the application to finish downloading any updates (shown in the message center).
10. Power on and plug in the LeapPad