This is what just came up when I tried to run a .mov file using Microsoft's Movie Maker:
Why not? Your software must know. Some test was done by Movie Maker and the wrong answer came up, so it bottled out and put this stupid message up instead of telling me what's wrong.
I gave up and installed QuickTime.
Back in the nineties (before Steve Jobs's return), Scott Adams wrote that Microsoft had turned Apple into Microsoft's R&D division. I sometimes wonder if nowadays Microsoft hasn't morphed into Apple's Marketing division.