回複：Does anyone know a DVD copy software?

There are two software for doing that, all free.
DVD Shrink allows you copy commercial DVD to a blank DVD. You can "shrink" the original to fit onto the 4.7 GB blank DVD. The quality of the shrunk DVD seems not effected. (you will need nero to do the burning though)

The other one is called DVD decrypter. It copies the any DVD to your hard drive. You can re-authorize the DVD (e.g. remove ADs, split it into two DVDs ..) and copy it back to blank DVDs (you need nero to do the burning), or you can use DVD shrink to copy from hard disk to a DVD.

Google them, there are instructions on the net to help you.