Greetings,
Security on the Internet, huh? It is a relative term, really.
I would say that at a
minimum you would need three types of programs, for a minimal level of security:
Firewall: Sygate which is (was?) free, but has been purchased by Symantec. Look for links the the latest version, 5.6, that are still available.
AntiVirus: I have used AVG, which has a free version, but lately, I have been buying NOD 32, which is just $39. According to Fred Langa, NOD32 is the best antivirus program.
http://www.eset.com/products/nt.htm
MailWasher previews your email and allows you to delete and/or bounce any junk email
before you download anything.
Always run Windows with a user that is
not Administrator, and I would highly recommend a hardware firewall/router, too. Here's a site that might have some other helpful hints:
http://www.firewallguide.com/, and I would also highly recommend that you read this:
http://grc.com/dos/grcdos.htm and then, check out the rest of that site:
http://www.grc.com/default.htm.