Speaker noise from laptop

[bryant]

When I hook up my laptop with Hoster to the mixer, then on to the speakers, then turn up the channel that the sound card is hooked up to, I hear a little bit of hum and sometimes a clicking noise. Is this typical of all sound cards, some sound cards, or some setting I can change to help alleviate this.
I have a new Dell 6000 (don't know the model of soundcard), ram =1gB.
Has anyone experienced this and made corrections? Just wondering what to look for here?