1. Check if mouse USB connector is secured to the USB port on your computer.
2. Reboot your computer and try connecting your mouse before the system initiates fully.
3. Make sure your mouse is not out of batteries.
4. Check if you need to install any drivers for your mouse.
5. Try your mouse on a different computer and verify if it works.
6. Check the manufacturer's website for the latest drivers or if there is any compatibility issue regarding your mouse and computer.