Windows 2000 Backup

I have a new machine running Windows 2000 Professional. I cannot get it to perform a backup using the Windows Backup program. The Tape drive is a Seagate STT20000A 10/20 Gig drive.
When I try to start the backup I get the following error “Required Media Missing” “There is no unused media available with the selected type”
The tape I am using is a new Segate tape.
So does anyone have any ideas on how to get it to see the tape.
TIA
Robert Payne