I often have the same problem. WMM2 does not provide adequate error messages for one to diagnose exactly what the problem truly is.
The message output by WMM2 on my system is
"Windows Movie Maker cannot save the movie to the specified location. Verify that the original source files used in your movie are still available, that the saving location is still available, and that there is enough free disk space available, and then try again."
This happens regardless of how many gigabytes of disk space are available, or that the source files are really there (they are!), etc.
Since my system has made movies using WMM2 under almost identical circumstances, with the only difference being a different source file located on the same disk, I presume that everything else should be fine, too - especially since the source file that it complains about can be read by WMM2 for editing purposes and display within WMM2 even after this supposed failure occurs.
Michael
----- Graham Hughes, MVP Digital Media wrote: -----
Hi Paul, want to give us some more details about how you are going about it,
and your pc specs, hdd space etc etc.
Does it throw up any error messages you could let us have details of, and
have you had a look at
www.papajohn.org there's plenty of help in there
Graham