Some video files may need to be cropped, like photos, before you are ready to use them in a movie. Windows Movie Maker, however, does not have a command for cropping video frames, as Photoshop does for still images.. You can instead use VirtualDub in conjunction with Movie Maker to trim your clips. Your movie files will not be locked out of one program if you open them up on another, so you can work with one file in both programs.
Import the videos into Windows Movie Maker using the "Import Video" command in the Movie Tasks list. Select the video in the list window and click the "Import" button.
Open the VirtualDub program and open the same movie file in this program.
Add a resize filter to VirtualDub, going to the Video menu, selecting "Filters" and the "Resize." In the "Filter: resize" window, select 720 width by 480 height for the dimensions.
Click on the "Cropping" button in the Filters window--it will be gray and unusable until you add the filter--to open up the Filter input cropping window.
Use the four controls in the cropping window to trim and crop the video frame along the X and Y axes until you reach the desired cropped image and press "OK."
Save the cropped video as an AVI file, going to the File menu and selecting "Save as AVI." Make sure you know where the file is being saved to.
Go back to the Movie Maker application and import the newly created video file. You can now drag the original and/or the cropped video clips into the Movie Maker storyboard to compare the two.
When you import a video, the program should already be set to turn it into clips by default. If the "Create clips for video files" check box is not checked in the Import File box, check it off before you click the Import button.