Ad-Aware PersonalDownload, install and run. The program will ask for an update. Click OK, then connect. Agree to install, then click Finish when it's done.
You should now be at a flashy-looking, yet somewhat complicated control panel. Just click "Start" and when the next screen shows up, make sure "Smart System Scan" is selected. Click Next.
Now go get a drink and watch some TV, this'll take a while. You'll know it's done when it plays a horrific tone that will frighten your pets. One this is done, click Next.
You'll see a checklist of all the crap Adaware's detected. Right click and click "Select All". Now click Next and enjoy the comfort that comes from Spyware being blasted into space.
This should take care of many problems. However, if you still have issues, try a bunch of programs.
Hope this helps. Mods feel free to add onto this topic.
Oh, and if you got the nasties from Kazaa, all I have to say is "lol".