This may be a driver issue. Depending on version of Windows, right click on the Start button and select Computer Management and then select Device Manager. Check to see if your mouse is listed under Human Interface Devices or Mice and Other Pointing Devices. Right click on the mouse entry and select uninstall, if you are prompted to delete the drives click yes. Click on the Actions tab at the top and select Scan for Hardware Changes. This should update the driver for the mouse.