Open avi file using VLC media player

When I opened avi file using Windows Media Player, I can only hear the sound but no video. I changed to use VLC media player and I am able watch videos.

VLC is a free and open source cross-platform multimedia player and framework that plays most multimedia files as well as DVD, Audio CD, VCD, and various streaming protocols. The input formats can be:
MPEG (ES,PS,TS,PVA,MP3), AVI, ASF / WMV / WMA, MP4 / MOV / 3GP, OGG / OGM / Annodex, Matroska (MKV), Real, WAV (including DTS), Raw Audio: DTS, AAC, AC3/A52,Raw DV,FLAC,FLV (Flash), MXF, Nut, Standard MIDI / SMF and Creative™ Voice.

VLC media player can be downloaded from:
http://www.videolan.org/