If you cannot connect Chromecast under Windows 8.1 for some reason and the online help system refers you to turn-sharing-on-or-off, then you will be pleased to hear that there is a fix, even the Chromecast support will not tell you:
Press the Windows icon key on your keyboard.and X key.
Click on Command Prompt (Admin.)
Click on Yes if prompted by your firewall pop-up.
Type netsh winsock reset and press enter
This way I have fixed the issue on 2 Windows 8.1 laptops, one x86 and one x64!
And now I am using it successfully with netfix, (I have seen it at a friend this weekend, and in Peru last year (despite some people living in Peru saying it's like like here and here), I have quite liked it. and I don't seem to be the only one :)
However I have still managed to only get it to work on my desktop computer just ones so I decided to rather use it together with my iPhone5S instead. It also has the advantage of turning the iPhone into a Chromecast remote control when I am sitting in front of the computer :)