You can try Movavi Flash Converter

You can try Movavi Flash Converter, the ideal tool for downloading video from YouTube, Google and other popularconvert flv to 3gp video-sharing websites and converting Flash (.flv) videos to any format for any device. step by step guide:Output formats: AVI (DivX, XviD, etc), MPEG4 (iPod, MP4), 3GPP (GSM), 3GPP2 (CDMA), convert flv to mp4 QuickTime (MOV), WMV, Flash (FLV), WMA or WAV. then you can import them into windows movie maker.Hope it helps. Contact me if you have any other question or you can use