This topic lists several kinds of security programs
that are available. Many of them are free. There are some other legitimate programs as well - if unsure about one, post a topic about it and ask.
This tutorial discusses means of staying safe on the internet
I personally use:
and ZoneAlarm Security Suite
I now use the free version of Edwido as a standalone manually operated spyware checker on my Windows XP SP2 Home Edition.
It's important to make sure that whatever product you get will be compatible with your operating system.
An important thing to consider when getting an Anti-Virus product is your e-mail:
I used to have Symantec Corporate Edition as my Anti-Virus, and my university e-mail account was IMAP, and Symantec - AKA Norton - doesn't
scan IMAP mail, only POP mail. I find it very interesting that the 6 virus files that Panda Online found were all
attached to my IMAP mail, and none to my POP mail. I do know that ZoneAlarm AntiVirus will scan incoming -but not outgoing - IMAP. I don't know about the others, other than Norton/Symantec which doesn't. (I find it very odd that the University strongly recommends Symantec when the e-mail system is IMAP).
Hope this helps,