Press the fn + F6 or F7 Key at the same time and check if it works.
If its not helping then try pressing Fn + F3 or Fn + F5 or Fn + F9 or Fn + F11 keys.
If still the problem persists get a USB mouse, go to Device manager, uninstall the driver for HID Compliant mouse, reboot and let Windows install the driver.
Regards,
Adrian