K++? I use kazaalite, which is kazaa minus the spyware and adware.
http://www.kazaalite.tk
And yea, you shouldn't let anything run at startup unless you absolutely have to.
just run msconfig, go to the startup tab, and uncheck everything
EXCEPT EXPLORER AND SYSTRAY. If you uncheck those, you just killed your computer.
They may not even be listed in there though, but still, watch out.