http://www.masternewmedia.org/news/2006/04/12/slow_computer_speed_up_your.htm http://www.schoolkit.com/kb/article.aspx?id=10016 Here's a few that show unnecessary processes that may be running(and, slowing your computer)
If you have any popups (and, even if you don't), use Adaware (it's free!)
http://www.lavasoftusa.com/single/mirror_download.php?f=g2Obc772A Click on the 'update' button every few days.
Also, try 'Spy-Bot Search And Destroy' (also free!)
http://www.safer-networking.org/en/mirrors/index.html(again, update regularly)
And, finally, try Peer Guardian. It's sort of like a firewall. But, blocks individual IP's(internet addresses)
http://phoenixlabs.org/pg2/(update, update!)
And, for a browser, I recommend Firefox. (Much better, more stable, more features,/etc than IE)
http://www.mozilla.com/en-US/firefox/ Hopefully this helps.