Many people caution against the use of Norton Antivirus 2004. I've not experienced nightmare problems with it. It does use a bit of power on pre-P4 systems though. The Symantec AV 9 client has the option to not-install email monitoring bits. I don't want the desktop to show annoying App YYY is sending email prompts, alerts, or otherwise. Since the system in question uses only webmail accounts I don't want this AV "feature" available at all. There are a couple of applications running in the background that regularly send email and the user need not be alerted to the email traffic in popups, alerts, logs, notifications, or otherwise.
What "memory resident" (idiot proof background scanning) applications would you recomend for an XP SP1 stand alone machine?
you need not recommend exclusively freeware. Since it will run on a P3-550 it should not be more of a resource hog than NAV 2004