It sounds like WMP is the problem. Try a different media player like VLC
(better choice) or Winamp
. If the media player isn't the problem, you could try using VirtualDub
In VirtualDub, open (Ctrl+O) the .avi file and under Video
, click on Direct stream copy
. Under Audio
, check Source audio
and Direct stream copy
. Then, in Audio
(Ctrl+I). Enter an offset and press ok. Then under File
, select Save as AVI...
(F7) and save as a different name.