Why Does My Cursor Suddenly Move Around Haywire?

Clean the surface of the touchpad with a dry, soft cloth to remove grease, sweat, moisture, or other liquids.

Adjust the sensitivity of the touch pad:

Click the Start button and click Control Panel.
Click Hardware.
Click Mouse.
When the Mouse Properties window appears, click the Pointer Options tab. Under Select a pointer speed: click to move the slider bar closer to Slow.
Verify that the Enhance pointer precision checkbox is checked.
Click OK.
Check to see if the touch pad still behaves erratically.

If the issue still persists, would recommend updating the touchpad driver. Please click on the link mentioned below to do so:

http://dell.to/uIo3ef

-- Enter the Service Tag and choose the operating system.
-- Download and install the drivers for touchpad.
-- Restart the computer. Please check if the issue is resolved now.

Please reply for any further assistance.