Digital Copy Disc will not play

Digital Copy Disc will not play
I have a DVD which includes a Portable digital copy of the subject film. However my PC disc drive does not recognise the DVD Disc and says that there is no disc in the drive. I can play other audio and dvds without this portable digital copy feature. My OS is windows xp home edition with service pack 3 with 4 Gb Ram and 500 Gb hard drive. I can play the DVD with the Portable digital copy in my laptop running OS XP Professional. Can anyone suggest what I need to do to get my computer to recognise this DVD Disc. Incidently the point of the exercise is to then enable the Film to be loaded via iTunes to my iTouch so I can watch the movie on the go.
Thanks

The only thing that I can think of is that DVDs change and your DVD-Rom may need a Rom update to handle the newer format DVDs. Check the DVD-Rom manufacturers site to see if they have a firmware update

I sincerely doubt you need a firmware update for your DVD drive.

My question is: what format is the file you're trying to play? That's probably where the issue is.

Is the DVD a factory-made one or a burned copy? Give us some more specifics.

The DVD is a factory made. But I now find that I'm having trouble with other DVDs. The drives (2) Optical NEC DVD +RW ND-1100A and Samsung DVD - ROM SD 616T have now become very in consistent sometimes reading the files OK and sometimes saying there is no disk in the Drive. So I focusing on this aspect first and tried "Microsoft Fixit Online". They recognised a problem but advised there was 1 problem needing attention and suggested the version of Microsoft Windows that I'm using may not support the UDF version that is used on the disc. So before I return to the original problem I need to sort out my two Disk Drives. However I suspect the route of the problem is related to Windows XP being able to read the DVD Files!

the media(dvd) is always a suspect in this kind of error however testing it in other computer would isolate your dvd problem.

Thanks Jaydeee for the info. Still trying other options at this stage.