Video players often need Codecs to run videos properly, and each video file may need different codecs, (Compression/Decompression).
Have you checked which codec your video file needs?
You can use a utility like G-Spot, (use Google), to identify which codecs the file needs, and then download a codec pack and install them. The codecs pack from the DivX free player is good enough for me, (http://www.divx.com).
recently i got a8n-vm assus motherboard with athlon 64 processor, now i was installed win xp32bit operating system it's installed proberly also i was installed motherboard drivers like audio video ..etc.. but when i open my media player the sound is coming but video never come then i was checked display properties the screen server setting 3d not working others working proberly so help me if need more information ..?