Poor quality image on computer, but great on TV

[claire]

I have just bought a JVC GR-D240 camera and a Q-tec firewire pci card. The picture quality on camera screen is excellent as is the picture when played directly onto the TV, BUT- when captured onto my PC using Windows movie-maker the quality is very poor and therefore poor when burned to CD , I have looked at Pinnacle software packages but dont know whether it is the software, the card, the cable or just me!!!