Why is my movie white?

You may run into problems with empty frames when taking digital video across platforms. This could be due to:

The compression format or codec (compressor/decompressor) may not be installed. There can even be problems with incompatible versions of codecs or self-contained applications (streaming media players).

With QuickTime files, vital information (in this case "atoms") is stored in the Macintosh resource fork. Resources are fundamental to the Mac OS and provide basic information that enable the OS to know what types of files are present, and which application will open them and how they display (see Apple documentation or The Cross-Platform Page). We only need to worry about how to fold the resource fork into the data fork -- a process called flattening. You can flatten QT files by checking "Playable on non-Apple computers" in the save dialog in MoviePlayer. You can also do this easily in Premiere and Media Cleaner Pro, or in specialty freeware like flattenMoov. Sometimes this won't work as expected, so you might need to repeat the operation as the very last step (don't even play it again until you try it in Windows). This problem should disappear with QT/MoviePlayer 3.0.

Sometimes there are just errors that are written into the file. In this case you'll just have to recapture or recompress.