A laptop is usually used with a so-called trackpad or touchpad that is built into the keyboard. This is used instead of a classic computer mouse. It can be disconnected, and if you’ve done this, it needs to be reactivated. This is done in Windows via the Start button and the Control panel. The setting can be found under the music icon. If you want to use a normal computer mouse, you generally just have to connect it via the USB port.