Coincidentally, I just helped my sister remove Norton 2005 from her brand new laptop (Norton was pre-installed) and install
Avast Home instead (and
Kerio 4.1.3 to replace the Norton firewall). Both Avast & Kerio are very lightweight, and I've been using the combination on 2 of my PCs for a good while now, with very nice results.
Well, Ι'm not exaggerating by saying that the poor laptop looked like it just heaved a huge sigh of relief!