Assuming you have a DVD-RW then you have only a couple of possibilities here
normally. Either the hardware is faulty or not properly configured. XP is
pretty good with picking up drives and other hardware, it's one of it's
greatest assets from my experience. Did this recently start/fail? Is this a
new drive? Can you provide us with more information so that we're not just
stabbing in the dark and hoping we're giving you the right answers?