In Windows 8, you can right click on Wi-Fi Router and you can show or hide Estimated Data Usage for any particular Wi-Fi router, check this post for more info. In Windows 8.1 Preview when you Right Click on any Wi-Fi adapter nothing happens, you can not show/hide estimate data usage, can not set metered connection, cannot forget any network, nor you can view connection properties. This small tutorial will guide you from where you can show/hide Estimate Data Usage.
