..I'm not sure you can write DVDs from windows explorer if that's what you are trying to use.
The formats the drive can support are important. Why don't you tell us the make and model of the drive.
DVD-R might not mean much - mine shows up as CD Drive or DVD/CD-RW drive in windows!
Go into control panel, then System, then Hardware, then Device Manager and look under DVD/CD-ROM drives for your drive.
For mine in there it says
_NEC DVD+RW ND-3100AD
which shows that it is the +RW format (probably - although to be sure i'd have to go and check the spec).
Let us know what you've got. You probably would need some software to write DVDs - usually they come with some.