Nikon D3100 video playback

I just purchased a nikon d3100, whenever i playback the videos on my camera, they are stunning-however whenever i play them back on my computer they are slow and freeze on each frame. How can i solve this? I would like to be able to edit them into windows movie maker which is also a problem because it doesn't support mov files. So how can i edit my movies in windows movie maker and have them playback smoothly?

Conversion will help this to a degree but what's really happening is your computer's video card is too slow. HD video generates a huge data stream and without a fast enough graphics card the video will do that because the card can't keep up.

When I converted to HD video I had to straight to Dell for an upgrade to my graphics card. It wasn't bad, about $80 and it made all the difference in play back.