I had my CF card reader die on me a few times (i.e., it suddenly stopped working: instead of being recognised, and then allowing me to access the CF card, it was "cycling", i.e., ...
I have a Windows 8 PC and my Nikon D3100 isn't showing up on it. It says USB device not recognized. I have updated the USB drivers, but no joy. Sadly, i don't have the disc that came with it.