Many of us us a mouse to navigate the web. Over time dirt and grime collect in it making it sluggish. Before you replace it, try cleaning it by disconnecting it from the keyboard. Take out the batteries. If yours is wireless, flip it over, turn it off, and take out the batteries. Turn the mouse upside down and continuously roll the wheel to loosen anything they may be stuck inside. Now use an alcohol wipe or microfiber cloth moistened with electronic cleaner to finish the job. Replug and you should be good to go!