A little while ago, Mihaly Krich ran a Kickstarter campaign to fund the PiConfig. It’s a little USB dongle that can be used to set-up the Raspberry Pi’s network settings from Windows or Mac. After you’ve set it up, you simply plug it into the Pi and the Pi reads the settings and sets up the necessary configuration files. Here’s a very well-balanced review of the product. You can buy a PiConfig from the maker’s website. I tried this product out myself and, although I had a few issues (it was an early model), the concept is sound and you shouldn’t have any issues using it to configure your wi-fi or LAN.