I have 2 sets of the Wireless Desktop 800 Keyboard and Mouse (although the mouse on both says it's a Microsoft Wireless Mouse 1000) and the one I use on my main PC isn't functioning correctly. I know it's not the batteries, and I know there's no signal interference or bad ports as I've plugged the other set in for the time being and that's all running fine. Also I have the latest drivers.
Both mouses have a green light after first being turned on, which slowly goes off after you start moving the cursor.
When not functioning correctly the mouse in my main set appears to have a green light present when the mouse is raised or the laser is exposed from the desk/pad - when i put the mouse down the light goes off, but the cursor doesn't respond - for the most part anyway, intermittently it does work (sort of like there's too much going on and the PC doesn't have the resources to show you the cursor moving, or it's frozen), and it's usually fine for an hour or so following the initial boot up. Sometimes the green light will come on when the mouse isn't moving but as soon as it moves, even the slightest, the light goes straight off.
The mouse that does work only glows dimly red when I'm moving the cursor, at any other time there's no light at all (I'm assuming this red glow is part of the laser when it's moving anyway and not the light itself).
I was guessing that there could be a loose connection somewhere in the main set but I'm not one for dismantling my mouse.