I have just edited my first video with Windows Movie Maker and now have a 38 minute film which I want to save but every time I try to save it to the recommended setting, when it has almost finished saving an error message pops up to say that there isn't enough space to save it yet my computer, a new one, has 1.72 TB of space.  I tried saving it to an external hard drive with 182 GB of free space - same thing happens.