Movie Maker stops responding at 55% when trying to save a movie

OK, I've been using Movie Maker in the past for a while, and never had this problem before. Its been 9 weeks and I still haven't figured out how to save this movie I created, so its pretty frustrating. I added a bunch of mp4 files to my movie and edited them around to a movie. I have also added a song(mp3 file.) The entire video is only 3 min and 53 sec long, but when I save "Recommended for this project", it freezes at EXACTLY 55% each time. The same thing happens when I try to save in 1080 HD display. I have Windows 7 and when I open up the comp settings it says I have 706 GB free in OS(C:) and 1.85 GB free in HP recovery. When I look at the .wlmp file in my folder, is says the size is 43 KB. However, the videos I added and then cropped and edited were much larger, in the thousands. I have already made the video as small as I could, taking out many transitions, but the rest I really do need for the project. I really want to save the file as a WMV to save to youtube. Can anyone help?? It would be much appreciated.