My network card only work in irq 3 but i dont know how change the irq of card. How can I do this?

Well, that all depends on your card...

First I would dig out the manual if you have it, and look trhough there, it should tell you if you can changethe IRW and how.

Secondly, I would try looking on the card itself, it may have a set of jumpers with the guide printed on the circuit boad. It would say somthing like: "IRQ JP" or something...

Lastly, I would try looking up the cards technical specs or manual on the internet, usually doing a google search for the card name and "documentation" or "manual" would do the trick. Of course you need to know the model and brand of your network card first.

Let me know how this works out....