shyamno said:
Is there any s/w through which incompleted torrent video (>50% of total) files can be viewed.
Run them through DivFix (just Google it). It lets you watch those partially downloaded avi movies (bittorrent video files are *.avi). If it can, it will fix them!
VLC Player works fine too in viewing incomplete AVI files. It can help you view them if it's not corrupt.
If it can't, then probably the file has got corrupt... The file will be missing the first few blocks in it which tells your media player what kind of a file it is, how big it is, what codecs to use, etc. On such is the problem, you can use an avi editor like Virtualdub (just Google it) to reconstruct partial files.