You need to download a program to facilitate Torrents, I use Azureus and Utorrent. I have 2 in case one gives me problems. Do a google search on these. Other popular softwares are Bitcomet and Mainline. The programs are free but you'll be asked to make a donation. It's well worth it.
I have uTorrent,I use it for mp3's,for the DVD's I use my moms computer,It has Azerus,and it says it cant find the file aplication or something.It only messes up on the DVD torrents!
That's unusual, it shouldn't make a difference if your downloading a DVD file or MP3. As long as you have enough space on the drive you are saving the DVD file on. I never seen that message before.
What file are you trying to DL?