[dba-Tech] cd-r or dvd-r

I bought a huge package of dvd-r's and the cd-burner won't recognize them. 
It is old, but there were no cd-r's and I thought maybe they were 
obsolete -- are they? Didn't realize mine wouldn't recognize dvd-r though.

Anything I can do to force my system to write to a dvd-r?

Susan H.