You can import files with the following file name extensions into Windows Movie Maker to use in your project:
Video files: .asf, .avi, .dvr-ms, .m1v, .mp2, .mp2v, .mpe, .mpeg, .mpg, .mpv2, .wm, and .wmv
Audio files: .aif, .aifc, .aiff .asf, .au, .mp2, .mp3, .mpa, .snd, .wav, and .wma
Picture files: .bmp, .dib, .emf, .gif, .jfif, .jpe, .jpeg, .jpg, .png, .tif, .tiff, and .wmf
You can also import files into Windows Movie Maker that have a different extension from the ones listed above, but not all file types will work when you try to use them to make a movie.
Microsoft Recorded TV Show files (with a .dvr-ms file name extension) that are not protected using digital rights management can be imported into Windows Movie Maker if your computer is running Windows Vista Home Premium or Windows Vista Ultimate.
Click File, and then click Import Media Items.
Navigate to the location that contains the digital media files you want to import, and then click Import.
You can import several video clips at once. For consecutive clips, click the first video clip in the list, press and hold down the SHIFT key, and then click the last clip in the list. For video clips that are not consecutive, press and hold down the CTRL key, and then click each clip that you want to import into Windows Movie Maker.
You can also import video files and pictures by dragging the files from Windows Photo Gallery into Windows Movie Maker.