Why is my PC freezing up?

As i have a Squeezebox 3 on order, i bought a WiFi card which i fitted this morning. I also took the dial-up modem out, because i was out of free PCI slots, and i'm now using a USB one.

Since i did this, my PC is freeing up. Not when i am using it, but everytime i leave my PC of 30 mins or so and come back to it, it's completely frozen.

Not really sure what to do really, any idea's?

change everything back to how it was. then change everything one by one. i.e. take the modem out and leave it for an hor put the card in and test then at least you will know what is causing it, then hopefulkly some knowledgable soul will be able to table a solution

I already have done, it's the WiFi card. Disabling it in device manager seems to have stopped the hanging. Have not got a clue why.

Everythings in my sig.

I'm going to update my BIOS, as looking at the Abit forums i think the AN8 Ultra has a few PCI issues.