To troubleshoot a wireless mouse, you must first identify the exact problem, such as the pointer moving erratically, the mouse being unresponsive to clicks or the mouse ceasing to work after several minutes of use. If the pointer moves erratically, ensure you are using the mouse on a smooth, flat surface. For optimal performance, use a mousepad.
The next thing to check is the mouse's batteries. Check whether the batteries are properly installed and whether they have enough power. A red light should blink at the bottom of the mouse if it's an optical mouse. If it's a laser mouse, check whether the power indicator light is on.
Next, resync your wireless mouse with its USB receiver. If the USB receiver has a Connect button, press it. A light should start blinking on the receiver. Locate the Connect button on the mouse and press it too. The light on the USB receiver should stop blinking. If your mouse doesn't feature a Connect button, refer to its manual to find out how you should pair and reconnect it to the USB receiver. If the issue persists, connect the receiver to a different USB port.
If the mouse still doesn't function properly after these measures, test it on another computer. If the same problem persists, the mouse has a mechanical problem.