Always install: HijackThis: http://www.majorgeeks.com/download3155.html MailWasher (or another): http://www.mailwasher.net/download.php
spyware doesn't rid your system of trojans. it's possible, likely even, that you have a malware running that simply replicates all these "critical objects" once they are removed. here is an excerise for you. open up your task manager and scrutinize all the processes running on your machine. (Google the names of each and every process running). If you discover that one of the processes is a known trojan, stop it, search for the exe or dll's on your system and the delete them. Search your registry for any references to these names, remove the keys. Backup registry before doing this though. If you don't know how to do this, LEARN. Believe me, it is a valuable excerise and one well worth your effort.
CCleaner is a good one. As far as overall protection once you have everything clean. AVG free and Zone Alarm. Both are free. After installing them I have not had a single issue.
Zone Alarm is a bandwidth hog. I tested it with dslreports.com it cut my download in half! I went from 7 meg to about 3, still plenty for day trading, but with a router and NAT I said cya to that resource hog.
Google "Hitman Pro". I just installed it and it's pretty impressive. It automatically installs, updates, and runs 5 or 6 spyware/malware programs, including Ad-Aware and Spybot. So just run that one program once a day and it does all the work for you. Kewl. If you have any of the individual programs in Hitman Pro already installed on your system you should first uninstall them before you install Hitman. H
Here is a video on how to clean up your pc and remove spy ware/startups. http://puretick.com/video/cleanup/