Trying to Uninstall Infected Norton Internet Security 2008 Program

I recently installed Norton Internet Security 2008 Program on a second computer and I have had a nightmare ever since.  Shortly after installing, I became infected with Perfect Defender 2009.  I think I finally have rid it from my computer after installing a couple of different spyware programs.  I don’t see any signs of PD2009 anymore, but I still keep getting a popup warning about having Win32.Zafi.B trojan program.  Because I think this is connected with the Norton, I have been trying to uninstall Norton, but I can’t even after downloading the unistall tool from Norton’s website.  One problem is that it keeps saying about the Live Update working and I must stop it.  When I go to Norton to do away with the Live Update, it will not let me open up the Settings to stop the live update.  I spent all day yesterday trying everything I could to rid my computer of all of its problems and have spent over $100 in various programs to help clear things up and I still have MAJOR PROBLEMS.  Does anyone have any suggestion on what to do now.  I am ready to just throw out the computer and buy a new one, but I don’t have the money to spend on that especially after already spending $100 to try to fix this one.  HELP, PLEASE!!!