Hi Elizabeth,
When you import AVCHD clips into an iMovie Event they are normally converted to Apple Intermediate Codec (AIC). This facilitates editing, in that the clips are essentially decompressed (resulting in much larger files than those on the camera). Note that these files all have the extension .mov which is simply a container for the AIC format.
The camera clips are in .MTS format and are highly compressed in order to preserve space. If you use iMovie's Archive feature, you will note that all clips in the Archive are in .MTS format and are identical to your original camera clips (with no quality loss).
Probably your best option is to create a Project in iMovie, then export it. To create a Project, in iMovie's menu click File>New Project. Drag all the clips in the Event to the Project window (or highlight sections that you wish to use, then drag to the Project). If you don't wish to do any editing in iMovie, simply export the Project using Share>Export Movie. Select the highest size available, such as Large, HD 720p, HD 1080p or other.
The file created from the export will be in H.264 format and will have the extension .m4v or .mov (depending on the size of the export). Both these types of files should play on a Windows PC, but I'm not sure about the editing side of things on PC's.
John
Message was edited by: John Cogdell
