Microsoft announced a new version of both the Windows Photo Gallery and Movie Maker for Windows 7 and Window 8. They have added a few new capabilities and are available for free from Windows Essentials 2012 (Web install).
For full details on this new release take a look at Windows Experience Blog.
If you look down through the Blog Comments you will see that there was some issues installing the update. You will need the newest version of .net and it isn’t part of the installation.
I have used Movie Maker in the past but I haven’t recently because it is a bit buggy and limited in features as compared to some of the simpler commercial programs that are out there like Adobe’s Premier Elements and Sony’s Vegas products.