NOTE: In Windows 11/10 now, you can also open Settings > Devices > Touchpad and click on the Reset button under Reset your Touchpad.
Reset Touchpad settings to default in Windows
In case anything doesn’t work well with the touchpad, or the previous troubleshooting has been messed with, the touchpad could be reset. The procedure for the same is as follows: From the Quick Link or WinX Menu open Settings > Devices. On the left-hand side, select Mouse and touchpad. Scroll to the bottom and click on Additional mouse settings. This opens the Mouse Properties window. The last tab is Device Settings, but it depends on the brand of the laptop. Eg. In the case of Lenovo laptops, the last option would be Thinkpad. On a Dell laptop, it could be Dell Touchpad tab. Click on Settings. On a Dell laptop, it could be Click to change Dell Touchpad settings. Find the option to change the settings to Default and click on it. It is different for laptops of different brands. Eg. In a Lenovo laptop, the option would be ‘Restore to default’. In a Sony laptop, another window would need to be opened by clicking on the option Default and then changed accordingly. For Dell, you will see a black button named default on the left top side. So you see, it will be different for different brands. If you wish, you can also disable or turn off the Touchpad if you do not use it. In the same settings where you reset Touchpad settings to default, you will an option to turn off or turn on the Touchpad. Here is the screenshot for a Dell laptop.
Toggle the switch to the Off position to disable Touchpad. But before you disable the Touchpad, make sure that you have a working mouse; else you may have difficulty in turning it On again.
Check this post if you want to change Touchpad Sensitivity in Windows.