Need ground Wire

[jtfoxman]

Hey all!
In my attic I have some wiring in my attic that does not have a ground. This wire works my light in the attic, 2 outlets in a bedroom and a closet light. I would like to add a ground wire to this since I would like to have a air conditioner in the bedroom and it would plug into a 3 prong outlet that is not grounded. Once the wire comes into the bedroom they started using 3 wire with the ground. But since there really is no ground to start with, the 3 prong outlets aren't grounded, it justs looks like they are. Would I only have to hook up the ground wire from when it first changes over to the 3 wire and run it to the basement water main.
Can I run it outside in conduit or without conduit, or what would be the best way to do it?
Thanks!

[kactuskid]

You can run a ground wire to the first box that has the 3 wire in it, then connect all the ground wires together in this box so the ground is carried through to the following boxs. But, this ground wire that you install must go all the way back to your main panel and CANNOT be attached to a nearby water pipe or the water main. What route you take depends on where your main panel is located. If your main panel is on the outside of the house then you definatly want to run the ground wire protected by conduit. If in the basement then just run the ground through the floor and up into the wall.

Below is a link that further explains the requirements to change a 2 prong receptacle to to a 3 prong receptacle.
http://www.codecheck.com/250_50_commentary.html