DVD and audio skipping

I’ve rebuilt a Compaq Presario 5000 after a hard disk crash. I’ve loaded W98SE and all available drivers from the Compaq site. Problem is that the DVD and audio skips while playing. It’s not distorted but it sounds like like it is jumping a track. The DVD is not listed in System Properties and I’m not sure if it needs a CDROM driver or not. Also I can’t seem to work out who the manufacturer is. There’s nothing on the case.