Can't remove software

Some how, AntvirusXP 2008 and 2009 showed up on my machine. Whether it was the kids or something I did it doesn't matter. I can't remove either one of them and they pop up constantly. I will not give them the satisfaction of purchasing these programs. I am running XP.

I have contacted them and of course since I do not want the programs, they do not get back to me. How can I remove it from the computer? It says I have hundreds of viruses and spyware, however, when I run other programs such as Symantecs and other free virus programs, it says that the only one that could not be removed was the one in the system 32. I went into safe mode and removed that one, I removed everything i could find in dos and now it is coming up again. This all happens with the Internet unplugged. Could you tell me how to remove these programs permanently and how do get all their threads so it won't come up again?
Jean
:cry