xp home problem

Hello all,

I am working on an xp home os. The computer is a HP with the os preinstalled.
There is no AV installed. I have tried to install norton av with no success. The
install seems to go fine but after reboot the program will not launch. I have tried
to connect to the internet to use mcafee or trend micro to scan for virus and
I can ping the gateway, and all other machines on the network. I can resolve
DNS but when I try IE v6 I get a search page could not be opened or the standard error that the server could not be found. I have tried to use system
restore to roll back to 4 different setpoints. I think that I have virus and spyware
problems and need to address them before anything else. I would be grateful for any suggestions that don't involve gasoline, a match, or a blowtorch.

Thanks in advance