In the final analysis, the only sure-fire way to edit HD video on any version of Windows, with any Windows-based editor (including Windows Movie Maker and Windows Live Movie Maker) is to use high-quality file conversion.

The good news is that a high-quality file converter is available for free.  Another free utility can be used to get just the right settings.

This members-only video tells you where to get the tools, and how to use them:

http://flipinfocus.com/video/video-conversion-windows-video-editors

You can create a template for any camcorder you have, and batch-convert you video to high-quality .WMV files.  You can bring video from different camcorders together in the same movie.  You can even capture live video from your computer screen, and incorporate those, too (e.g., for video tutorials about software or websites.)

Here are the links mentioned in the video:

• http://sourceforge.net/projects/mediainfo/
• http://www.microsoft.com/expression/products/Encoder_Overview.aspx