xp shows dvd writer as standard cdrom drive

The DVD writer in my HP Pavilion T3155.uk, will no longer write DVDs.

Whenever I try it says 'Invalid Function'.

The drive is an HP HP dvd640c, my operating system is Windows XP SP2.

I've seen various posts about upper and lower filters in the registry, but

they don't specifically mention this problem.

If anyone knows what I can do about this, I would be grateful for any

suggestions. Updating the driver and firmware worked temporarily.

Thanks in advance,

--

Steve