So I rendered a video on movie maker for 1280 by 720 and it looks good but it's still not hd what can I do to make it look better?
What do you mean by "it's not HD"? Your video won't look better than your raw footage is. You must render your video at the same resolution as you recorded it.
If you recorded your video in 1280x720p then you must render it in 720p.
If you recorded your video in 1920x1080p then you must render it in 1080p.