If you have DVD-RAM disc in a cartridge and your DVD recorder does not support cartridges, you need to remove the disc from its cartridge.
DVD-RAM disc in cartridge
First you need to remove disc removal lock pin, by using the pointed end of a ballpoint pen or something similar:
Removed disc lock pin:
Next, open the lid, by using a ballpen to press the indentation located on the left side of the cartridge:
Open the lid:
Remove the disc from cartridge:
When returning disc to cartridge, make sure that printed side of the shutter and printed side of the disc are on the same side.
More Information: [Using DVD-RAM disc under Windows XP->using-dvd-ram-disc-under-windows-xp]