Hello,
I bought a Nano from Littlebird electronics and another through ebay. The first one I have uploaded to it many of times and had some trouble with data corruption so I bought the other one to ensure that it was not the chips fault. To my discovery it was my software that was causing the issue. Any way my point is that I have had 1 nano which I have uploaded maybe 50 times and another also 50 times now as I keep swapping and changing. Now I can not connect to either of them because my windows 7 keeps telling me that the device has not installed correctly. I have pointed windows to the Arduino drivers and still no solution. This has been happening for a while on some of my usb ports but if I changed to a different port it would install correctly. Now all of my ports (4 of them) will not install the correct drivers. What is going on here it seems like a common problem but do not see any solutions. Why has this suddenly happened, is it windows update that has caused this?