1) plug in a usb mouse
2) go to control panel and open device manager
3) find the touchpad, possibly listed under input devices or touch input.
4) right click and select disable this device
5) see if same problem still happens
6) if it does it’s not the touchpad, if it fixes it go to the laptop...
Have you checked you’ve got the correct driver for the trackpad? Try plugging in usb mouse and disabling the trackpad entirely and seeing if that resolved the issue.