After upgrading OS on my Sahara NB 610 notebook from Win Starter to XP PRO, no sound or video would work on my DVD/CDRW. (Don't know if disk was reformatted - done by colleague). Eventually fixed CD sound by loading RealTek AC97 driver (after much searching around on the Sahara site and on the Web), but DVDs still don't play sound or video. Everything else on PC is working fine. DVD previously worked correctly. Any suggestions?