Microsoft wireless mouse 3000

if you have not uninstalled it,then you don't need to reinstall it
is there a light on the mouse?
If no change the batteries or else
there would be a connecter connected to the back of the system,you need to unplugg it & replug it back,after that you would be getting a small baloon tip at the botton right hand corner,now you ahve to press the connect button on the reciever & immediately press the connect button on the bottom of teh mouse.now your mouse should be working

I had the same problem with two of my Microsoft Wireless Mouse 3000. I finally called Microsoft (do not have to wait to long, max 3 minutes) and they replace the mouse without me having to send the defected one.

Tech and replacement line: 1-800-360-7561