Network not appearing

The network appears for my phone, my Ipad, my husband's laptop, his phone -  BUT not for my laptop.   I can see all the networks set-up by neighbors, but not the Xfinity for our house.  I tried to add it manually, that did not work. 

I called the Xfinity Help Desk; I read through the Forum.  One other user had this problem, but this person claims that the problem "magically disappeared" after a certain number of restarts. 

I would like a solution other than "magic". Thank you.