I'm using a wireless logitech mouse and twice this has happened. When I load the computer the mouse works for a while then the arrow freezes and won't move. So I change the battery and remove the dongle at the back of the tower before replacing it. Then turn on the tower and the cursor has vanished. I've only had this mouse since last month, because I had the same problem with my last mouse (also a logitech). Am I better getting a wired mouse?