I use Avast free on both of my XP SP1 machines and it works but as with any utility they have limits and research & development isn't as good as the products that require $ and yearly more $, IMHO. But it works well enough to remove most crap and the developers do work with you to help if the need arises.
Now (again IMHO) one has to have layered security besides AV & some firewall. Lavasoft & the plug ins, SpyBot Search & Destory, Spyware Blaster and Spyware Guard are all free and work well with most other install security utilities. All of which I use plus several paid for utilities. the new ewido 4.0, Spysweeper & PC-cillin Internet Security 2006 (both came with the new HP) and Counter Spy. But I have 2048MB of RAM with a 2.8 GHz duo CPU. yet I also run these on my to lesser PC's with only 512 MB/768 MB of RAM and have no problems with the processor.
Edited by mlurp, 17 July 2006 - 01:57 PM.