You can only install Movie Maker as the Essentials bundle, a free set of lifestyle and utility apps for Windows 7 and Windows 8 that also includes Windows Photo Gallery. The single installer for all the Essentials apps offers an initial option of installing everything or letting you choose which to install. Since you may not need the Family Safety program, for example, I recommend the latter installation option. Movie Maker installs as a desktop application in Windows 8, and unfortunately, is not available for Windows RT tablets (though they do have alternatives like ArcSoft ShowBiz).
One of the things I really like about working in Movie Maker is that most of the effects, transitions, and themes preview automatically when you just hover the mouse cursor over their buttons. Another plus is the undo and redo buttons are right up top—video editing is a very trial-and-error process—but I suppose it's too much to ask for a history window in such a simple application.