You have to save the original DVD to harddrive and then use Nero Recode to Recode/burn it so it fits on the new DVD. (Unless you bought dual layer DVD-R, the disk is smaller 4.7 GB as oppose to probably 7GB on the original)
The DVD Decrypter is a program that helps you remove the protection so you can backup your original DVD. Turn on the program then copy the disk to your harddrive
Just read through the guides at
www.videohelp.com
This really shouldn't be discussed here since this is a P2P forum and might be taken the wrong way