This article explains how to unlock the mouse on a Lenovo laptop. These instructions apply to the built-in trackpad on all Lenovo laptops and external mice.
Touchpad: Enable/Disable | Quick Tips from Lenovo Support
If your laptop's trackpad is locked, there could be several reasons for this:
Just as there are multiple reasons why your laptop mouse is locked up, there are also several ways to fix it. These steps are helpful if you have another mouse connected to your laptop (if you don't, skip to the keyboard instructions below).
Turn on the touchpad with the keyboard. Some Lenovo laptops have a hotkey that toggles the trackpad on and off. Look for a key with an icon that resembles a touchpad. If your computer has one, it's probably assigned to one of the function keys on the top row, so you'll need to hold down the Fn key and press the button (for example, Fn+F6).