Making Backup Copies Of Dvd's

[UNCLEAL]

I have a _NEC DVD&RW ND-1100A combo burner installed on my Dell computer.I need to make some backup copies of some of my DVD'S.What type of DVD-recordable disks will work on this burner? (DVD-R,DVD+R etc.)? I tried making copies using DVD-R disks,they won't work.Receive message "not a recordable media" or "please insert a recordable disk in drive".

UNCLEAL

[Baser-X]

You'll need to check your manual or call Dell to find out which type of DVD discs it supports.

[mawil]

I have a NEC ND-1100A and it uses DVD +R.