Conditions in www.nordicsemi.com/.../Why-can-Master-Control-Panel-not-find-my-Master-Emulator-Dongle have been met, ie all components of PCA10031 have installed successfully with the versions below:
Master Control Panel v3.4.0.8098 JLink CDC UART Port v6.0.2601.5 Portable Device JLINK v6.1.7600.16385 J-Link Driver v2.6.8.1
PC running Windows 7 Enterprise 64bit.