I recently read about this new editor called Lightworks, it's supposed to be very flexible, open-source, have a lot of features, and the best part is the price-point FREE. Check it out, it could be a great upgrade if you currently lack a NLE beyond Windows Movie Maker, since this has a ton of advanced features, including being able to edit HD, and being able to handle many different codecs, it can't hurt to at least try it out. So go check it out, or just head here and download it directly.