why do some cds not play on my computer

I have two drives at home and one at work and own some of the discs mentioned, and they all play with no problems:
Windows XP home, plays fine in WMP, iTunes Windows XP Pro, plays fine in WMP Really stumped why there would be an issue. IFPI is the international copyright organization for music media.

All legitmate CDs, DVDs, and Blu-Rays have an IFPI code in plastic moulding to identify the pressing plant, and also have one in the matrix to identify the recorder/master used. It is not a form of DRM. If there is DRM, it would be a separate issue. Hi Ajay K, Thanks for taking the time to reply.

I have done a bit more digging, and yes it is MP 12, I was under the impression that one had to download it. I didn't realise that it was included in W7. RE Hotel California, originally all the information was there re album info', under the rip status column each track has the word pending.

When the rip tab was checked this changed, instead of seeing ripping, the word error appeared next to each track. As well as not ripping the tracks, I couldn't play them either. Now when I repeat the operation, a box appears telling me that "Windows Media Player cannot rip one or more tracks from the CD".

So far this only affects about half a dozen CD's, which is strange as I would expect it to affect all or none. Playing the CD's on a PC running Vista, the same discs play, but will not rip.

One disc that will not play or rip, ripped perfectly well in Vista. I am worried that if a solution is found to enable these discs to play and be ripped, that this will adversly affect discs that can be played currently. Could the discs that won't rip be copy protected. If so can it be resolved?