noob question about burning DVD

please help!
I can't write DVDs even though I have a cd-rom drive.. why is that?
do i need some kind of program to install support for DVDs maybe?

oh,  I use DVD encrypter to write the ISO to the DVD

no. you need a DVD-RW drive.

http://www.newegg.com/Product/Product.asp?Item=N82E16827106055

once you have that installed you can burn dvd disc.

if you make 1:1 dvd isos, make sure you buy Dual layer dvd disc.
dvd+R DL