Touch-pad problem on inspiron 15r 5537

My Inspiron 15r 5537 touchpad is not showing in device manager, control panel and task bar.

this happened when I switched my laptop from window 8 to window 7. i again reinstalled window 8 but the device manager just shows the regular mouse and no touch pad.

It is awful not to have the gestures as it makes browsing too much difficult.

there is no app or software to configure touch pad or gestures. the normal touchpad is operating okay but gestures are not working and there is no option in control panel to manage or set touchpad i have searched using the search option and manually.

Please help.