I just purchased this kit and am having similar problems with Windows 7 as other users are also. As a disclaimer I want to say that I know nothing about how device drivers work but I did a quick search on the internet and found that there have been about 5 more updates to this driver since the release posted. http://sourceforge.net/projects/libusb-win32/files/
I tried downloading the latest driver and updating it but it kept telling me that I had the most up to date driver. I'm guessing that since this is kind of a generic open source driver that it wold need to be configured first for the particular device before it can be recognized. As a side note I looked through the changelog and it did say that the newest driver is now SIGNED, which would probably fix most of the problems out there. If anyone knows of how to configure these drivers and wants to pass along the settings I would more than happy to test it on my machine.
Wayne

