To turn off the touchscreen on a Lenovo laptop, you can follow these steps:

1. Press Windows key + X to open Device Manager.
2. Find the Human Interface Device option and click on it.
3. Now, click on the HID-compliant device option.
4. Right-click on the option and choose Disable.

You can also enable and disable your touchscreen by following these steps:

1. Press Windows key + X.
2. Select Device Manager.
3. Find HID-Compliant touchscreen under Human Interface Devices.
4. Right-click the device name and select Disable or Enable.