Although you have administrator rights, the installation of NWBC is started without actually installing NWBC. The files are only extracted and then cleaned up immediately afterwards. No installation is run.
Window's User Access Control (UAC) mechanism sometimes prevents the setup application from starting the next phase, which actually installs NWBC. To ensure that the setup application is running with the correct rights, open the context menu of the setup executable and choose Run as administrator. The installation should now run correctly.