The Nexus S does things a little different in terms of the connectivity to a PC. First off, it seems to use a bog standard USB driver in Win 7 rather than a proprietory one - does not show up in device manager as anything special. Secondly, you need to look at your phone as it will initiate the connection to your PC via input on its touchscreen interface. It should ask you whether you want to connect via USB, folowed by a warning about disabling apps whilst on the USB connection. If you don't even get to the stage where the Nexus S recognises being hooked up to a PC than its definately a cennectivity issue. I'm on Windoes 7 32bit and had no problems with the device being found first time and any subsequent times. It could be also the USB data cable. I found that smartphones are rather temperamental when it comes to physical connections with cables, particularly in a 64bit environment. Try another cable and see if this solves the problem. If you have access to another Windows 7 machine try hooking it up to it as you do not need to install any software or drivers.