A friend of mine lives in an old house with no grounded outlets. The landlord's electrician says that to install grounded outlets, he would either have to break into one of the walls or else do some kind of piggy back operation (?) at the fuse box. For some reason, neither of these possibilities is considered desirable or feasible, maybe because of expense or safety. At any rate, my friend is wondering what the alternatives are for safely operating a computer in that house, as well as other devices that require 3 prong outlets. It's not just a matter of protection against electrical shock to the user of the computer, but also of damage to the device itself.
I'm aware that there are 3-2 prong adaptors that will plug into a 2-prong socket and which have a lead wire that attaches to the screw that holds the face plate of the socket in place. Allegedly the lead wire provides the ground since the screw is allegedly grounded. However, I've seen some sockets where that screw is not connected to anything and is certainly not grounded.
What is the right way to deal with this problem, given that no one seems to be willing to pay the electrician to do the things he has offered to do?