Hi, just posting this in case someone finds it useful.
I was connecting a friends Sansa Fuze 4gb(bought new a few months ago) for the first time to my Windows 7 computer, and it wouldnt install correctly no matter how many times I tried. Got the Error 43 issue. Tried it in my Win7 laptop and same thing. Tried switching between MTP/MSC/Auto. Finally about to give up i pressed the sanza cable connector HARD into the player and held it firmly without moving. It then registered and installed the driver correctly. So its either the cable or the player, going to get a new cable and try that.