How to Unlock a Laptop Mouse
Plugging in an external mouse to a laptop will commonly disable the built in touchpad automatically. This can be frustrating if you still want to use the touchpad while having a mouse plugged in, but luckily the process of unlocking it is relatively easy. Just be aware that your system will still accept input from both devices, so your control of the mouse pointer will be hampered should either device detect movement.
Open your "Start" menu and click "Control Panel." It may be located under a heading of "Settings" depending on your configuration.
Double click the "Mouse" icon in "Control Panel" to open mouse configuration options.
Click on the tab with the word "Touchpad" in it. Look for a sub-menu labeled for external mouse settings.
Uncheck the box that states it will disable the touchpad when the system detects an external mouse is connected.
Press "Apply" and then "OK" to save your settings.