Enable the touchpad on your laptop via the Control Panel.

Aside from the hotkey combination, the touchpad can also be activated or deactivated from the Control Panel. Many Dell users who experienced touchpad issues following a Windows update reported that enabling the touchpad from the control panel fixed their problem. Follow the steps below to enable the touchpad from the Control Panel:

• To open a Run box, press the Windows key + R. 
• Then, to open Control Panel, type "control" and press Enter. 
• Navigate to Hardware and Sound, then click on Mouse and Touchpad. 
• Next, inside Mouse Properties, click on Additional mouse options and check to see if your Touchpad is enabled.