It is nearly impossible to get a bit-for-bit transfer from Windows 7 for audio. It's mixer combines the output of each running program together, and resamples it all to a fixed frequency (usaully 48 kHz, but that can be changed in the control panel, you may want to bump it to 96 or 192 kHz).
That said, with the volume control set to 100% it does a very good job of preserving quality, it just isn't the identical information you'd get from a stand-alone CD player streaming the bits from the surface of a disc.
