Anti-Virus: AVG or AntiVir personal
Anti-spyware: Spybot s&d, ad-aware, spywareblaster, microsoft anti-spyware (u don't need all of these but they are all good. but install atleast 2)
Pop-up blocker: Get firefox
i also use winpatrol, its a great tool for finding problems. and its free.
go to "majorgeeks.com" they have lists of all the great free downloads.
heres a link to winpatrol at majorgeeks " http://majorgeeks.com/download.php?det=3380 "
PENTIUM 4 3.06 GHZ WITH HT TECHNOLOGY