Help with Unwanted Remote Network and Changed OS!

Help, my mac has been compromised by an unwanted network. If you do an install form the disk, it says that it is putting it in one location, erasing it and loading it from a network. All of the applications are changed. It is a late Dec. '06 Black Macbook. I have been at the Apple store at least 25 times. I just got leopard and a portable hard drive. That showed it had windows 98, a legacy OS, and a different Mac OS. Then, it would not work. It also had something called bounceback. I cannot communicate with my son in IRAQ because I cannot use any IM apps. My mobile phone is somehow involved too. It takes my text msgs and calls and sends them somewhere. The computer takes every site I visit and all my mail and sends those pages somewhere. I am using a wireless router by verizon for fios. It has a WEP password. I have airport extreme hat I want to install with 2 x-boxes and other computers that are windows. If I download an installation or software update, it will not install it, but creates a separate disk image. Applescript (it's not OS X) gives instructions to change everything. Automator works with it. Garageband, the Chess game thing and Address book, as well as the mail app. and Itunes all figure prominently into the changes. I just entered a long help message that it would not let me send. Please help me get rid of this unwanted remote network. It could be someone I know that had access to my home, computer and phone through other phones on my account that worked for the phone company as a tech for 20 years. Help!