The sound from the computer is not going to sound as good as that of a good CD player. It is not a debate it is a fact. If you could get the bits to the processor perfectly the two would sound the same but you can't. The computer has a crappy power supply compared to a good CD player and there is more stuff inside to cause interference which causes bit error. Every processor has to have error correction without it the thing would never work. A good player gives this error corrector very little work to do but you computer will give it more and in turn more chance to get it wrong.
Though MDS has already covered this, I thought I'd make a few comments. Firstly, the performance of CD playback will depend on the quality of the devices you are using, whether an internal computer CD player and audio card or a separate CD player.
The audio data read from audio compact discs are encoded with error correction to allow for dirty fingerprints, scratches etc. on the surface of the disc. All CD players must decode these data read from the disc, so all must incorporate error correction circuitry. So long as an error is detected, error correction is perfect, because if a bit with a value of 1 is known to be in error, then all the decoder has to do is invert the bit. If the a CD is particularly dirty, the player may have to mute playback or interpolate audio samples.
The ability of a CD player to read dirty discs depends on the performance of that device, whether a separate CD player or an internal computer CD player. I've used older, good quality separate CD players in the past, Denon, Rotel, which have had enormous difficulty reading some discs, i.e. with constant skipping, which more modern and cheaper players play perfectly well.
