I think your burner software has the formatting function- if it doesn't, you can download a freeware burner program or trial of nero or roxio- i tried "Burn4Free" that I downloaded from WebAttack, a freeware sight.
You also micht try to open my computer, and with the rw disk in the drive, right click the burner drive icon, and select "format" or "propertis". From foperties, look for a format option.
You also might check the drive manufacturer's website and download and install any firmware updates.