Wireless or Ethernet would have no effect on that.
Try the following and see if it fixes it...
1. Go into "Control Panel".
2. Click "Hardware and Sound".
3. Now click "Mouse and Touchpad".
4. Now go to "Additional mouse options".
5. The Mouse Properties window will open. In here click on your device.
6. Make sure your device is set to enabled. If it isn't then click "Enable Device".
7. Exit both that screen and "Control Panel".
It should work now.
You may also want to try reinstalling/updating the Synaptics Driver.