WMV, or Windows Media Video, is a Microsoft Windows-based file used by most media player and video programs on PC systems. However, if you have a video that you want to trim some excess content from, it is possible to do so with the pre-installed Windows Movie Maker (on Windows computer hard drives starting with Windows XP). After editing the clip down to size and re-exporting the content, it is saved as a smaller video file, saving you room on the hard drive.
Open Windows Movie Maker. Click "File," "Open File" and choose the WMV file you want to trim.
Click and drag the video file down to the time line at the bottom of the video program. Clips are placed into the time line to be edited and represent the entire edited movie. Once placed into the time line, the video is represented by an image of the first frame of the video. (However, you can see the actual video on the preview monitor.)
Click on the left side of the image. The mouse cursor changes to a bracket facing the right. This means you have entered into "Trim Mode." Drag the cursor to the right to remove the beginning of the video file. The farther you drag the mouse cursor, the more content you trim from the beginning of the WMV file.
Click on the right side of the image. The mouse cursor changes to a bracket facing the left. This enters you into "Trim Mode" again. Drag the cursor to the left to remove the end of the video file. The farther you drag the mouse cursor, the more you trim from the end of the WMV file.
Click "File" and "Save File As." A save window appears on the screen. Title the video file to your liking, choose a location to save the file and click "Save." The trimmed video file now exports to your computer.
Open a media player installed on the computer (such as Windows Media Player or QuickTime). Select "File" and then "Open," and choose the trimmed WMV file. The video loads onto the screen. Click "Play" on the video media player, and the video file plays on the computer.