I have also have a Lenovo (B570) running Windows 7 64-bit and have the same problem. When plugging in the iPod Shuffle (2nd gen) Windows attempts to locate and install the correct drivers, but does not find them. Instead, it says the USB device is not recognized. As Windows cannot install the drivers, iTunes cannot find the device so it does not show up. I attempted the 5 Rs (including re-installing iTunes) but this did not solve the problem. I went to the Lenovo support website and downloaded and installed the lastest USB drivers but this still did not solve the problem.
The iPod Shuffle works on my brand new Mac mini as well as my Dell Latitude E6500. However, it only works as a USB 1.1 device on the Dell.
If anyone can provide assistance I would greatly appreciate it. Thanks!