I have run into this issue twice this week so I though I would share. We had a client report their mouse was broken. She could sometime click on things, sometimes not. The mouse would sporatically not move, etc. etc. What was the fix? New batteries.
If your mouse does not move at all, you may need to reestablish the wireless link. Most wireless mice have a ‘connect’ or ‘reset’ button on the bottom of them. Just press that.
You may also want to take a cloth and clean off the laser optics on the mouse as well (the red light).