How to ground an outlet without a grounding wire

You don't. You replace the outlets with GFCIs, and label them "no equipment ground".

There are only 2 ways to get a grounded outlet. Replace the wiring with wire that has a black, white, and green or bare wire in it. You can also run a green or bare wire to each outlets grounding screw and then back to the fuse/braker box. With only 2 wires you can not get agrounded outlet.

GFCI would give you pretty good protection.

Also, if/when it is convenient to do so, run a separate ground wire from the nearest grounded outlet (don't use water pipe) to the ungrounded outlets.

Yes you could.

But it couldn't power anything.....

Jeff

Why don't use water pipe? Straight question.

If you had fault currents running through the water pipe, and someone like a plumber, cut the pipe in the process of doing some work, he could get electrocuted. There was a time when connecting a non grounded outlet to a cold water pipe was code, but now only the first five feet of water entrance pipe into a building, would be acceptable

Hey Spud did a lot of research on this topic did ya? Google don't work for ya? Geez lazy ass...

Well, actually, you can't. Not safely.

what sort of existing cable is there? if its BX you can ground to the box provided it tests ok...

I am saddended no one mentioned this. its a common fix