I am an ignorant IT user myself, knowing almost nothing about a computer except logging on to surf on websites.  But my son is an IT buff.

Last time when he came to our place, he installed a whole set of desk computer for my wife.  He bought everything needed from computer stores: a host, a moniter, accessaries,  and set them up piece by piece to make a beautiful adult "toy".  (Later on he told us he learnt how to install a computer when he was just a high school student.  We had not known that before.)  This time when he came to my place for spending Lunar New Year with us, I wanted him to do me a similar favor lest I should take my notebook flying across Pacific Ocean any longer.  He did, and I got a brand new desk computer myself now: a compact host, wide-angled moniter, a streamlined keyboard, and a pair of amplifiers. 

But Just as he left for his home yesterday morning, in the evening I found my new computer was down for unknown reason (I clicked in to seek assistance from "troubleshooting", and the message told me it was due to no wi-fi available, but the other devices in the house were working, i.e. my cell phone, Ipad, notebook, TV, and so on.)  Suddenly, I was left high and dry, for I had absolutely no idea how to restart my new computer.  Early this morning, I called my son for his help.  Through audio-visual conversation on LINE, with my wife holding the Ipad facing the monitor, he guided me to comply with the instruction displayed on screen, step by step.  In less than five minutes, he made the computer run again.  I should jot down those steps, but I did not.  Well, son, see you next time in case there is any trouble happening again!