Bundled software can be stopped by your firewall, for example anything coming with "kazaa" let's assume, you can block all connections from yet only allow kazaa client to connect, this will prevent 3rd party software bundled from connecting and sending data over the internet, hence it's blocked yet still on your machine.
Most bundled software can be removed within add/remove programs, some might require that the client which came with the bundled software be removed also.
Mind you some auto-add to start-up to begin silently on boot up, to remove this click Start -> Run -> type MSCONFIG and hit ok, go to the startup tab and uncheck the ad client in the background, next time you reboot you will not be running the malware.
Just some useful tips.