Vista - Auto update now cd/dvd drive doesn't work

I've got HP Pavilion a1730n desktop with Vista Home Premium and last week the
automatic updates created a problem again. Windows Media Centre will not
read or write to drive E: cd/dvd drive. I can't even get it to play a
purchased cd.This exact thing happened once before and a tech told me which
update to uninstall ... worked perfectly.

Does anyone know which update created this problem???

I've spent hours on the help and tech pages of HP and Microsoft and can't
find any answers. I've tried updating the drivers, uninstalling and
reinstalling...still nothing. Yes, I've read the article regarding when a
system is updated from XP to Vista but this doesn't apply to me. My system
came with this OP SYS.

Thanks for any help you can give me !!