It's not built in anymore. Microsoft took it away.
I can't remember exactly what the last name was that they gave the remote-assistance tool, but they removed it from all but so-called "pro" Windows... the one used by the LEAST-likely people to need it.
More anti-user BS from Microsoft. The baffling aspect is how Microsoft thinks it benefits from screwing users like this. I can't wait to buy my parents a Neo and shitcan Windows from their home forever.