IF you deal with a respectable repair/computer service, they will be MORE than willing to come to your house and pick up the computers! All you need to do is explain you and your mother are not physically able to bring them to their place of business. If they are NOT willing to do this, chances are you do NOT want them doing any work for you either. I know that Circuit City, Best Buy, and Computer World stores all offer this service. Certainly, you are not out in the boondocks and should have access to one of them or another reputable place.
Many of the things you have repeatedly mentioned as big problems should not be. Obviously, as I said before, you need to quit looking at sites and tinkering ie "A little knowledge is a dangerous thing." Your modem and router are not going to take your entire memory and when you use a scanner, of course your CPU is going to jump. It's the nature of it. Having umpteen virus programs installed does NO good whatsoever if they are NOT running properly, they cancel each other out, and running partial components of numerous ones is asking for trouble.
The bond that links your true family is not one of blood, but of respect and joy in each other's life. Rarely do members of one family grow up under the same roof.-- Richard Bach [i]Illusions