@ Shani: I always thought spyware doctor was trialware, and I think it still is-
"The trial offers time unlimited real-time protection (free spyware blocking), but does not remove threats detected during on-demand scans, updates may also differ to those supplied to registered users."
Personally, I like AVG. I used AVG with Spybot, ZoneAlarm (firewall), and Ad-Aware with no problems. If you like the all in one packages: there is bundle of software from
Avira, it includes free anti virus, AV removal tool, anti-rootkit tool, boot sector repair tool, file recovery tools, NTFS4DOS, and a "rescue system" tool. I don't know what the last two are, but I can say that every German and their mothers use Avira products. They still need a firewall, and they also all use ZoneAlarm.