Press Windows + X and select Device Manager from the list.
Find Keyboards in the list of devices and click the arrow to expand it.
Right-click on the internal keyboard and click Disable. If there is no Disable option listed, click Uninstall.
Click File>Exit. Your laptop’s internal keyboard should now be disabled.
Note: If you had to choose Uninstall instead of Disable in step 4, the keyboard will be automatically detected and re-installed if you ever have the Device Manager scan for new hardware for some reason. If that happens you’ll need to repeat this procedure in order to uninstall it again.