[ranjan2001]

if they are rar file while unzipping them, it will give errors that part no.?....is corrupted, try downloading that part only & save it in a separate folder & once downloaded replace it in the original directory & then try ur luck.

I am not much aware of torrent clients working so cant comment much on that, but try re downloading in a new directory & there is something called hash checking which is meant for confirming the 2 files, I dont know how it works but its meant to check the file authenticity.