You might not have the right codecs needed to view the movie. Load the video in GSPOT and find out. If GSPOT reports nothing and/or you get a FourCC code of "0", then you most likely have downloaded a fake file.
the G-spot program will show u the necessary codec you will need to play the file however, u could also jus simply right click the file and go to summary and se the codec the file was encoded with then get the necessary codec however this summary doesn't list the audio codec ac3 filter decoder does the trick for most files
im havin the same prob with a .avi file. got Gspot it says 1 compatiable codec for the video and 1 for the audio. wtf is wrong
If its a divx codec that is compatible but doesnt work, download the newest version of the codec. If its an xvid codec then download FFDshow.
You may have conflicting Codecs... have a visit to http://forums.afterdawn.com/thread_view.cfm/48608 to see a working codec combination