PC audio output via USB

The files bit rate is the files bit rate, unless you are asking if your pc can upconvert in front of the DAC. I haven't seen up converting onboard sound cards stock, but they are available aftermarket. I doubt there would be a sonic benefit if you are using a decent DAC, your file will still be @ 16/44.1 and your DAC needs to do its job.
I don't know about media monkey, but foobar and jrivers will both show what rate your file is playing at.

Classikaudio,
I'm sorry that I forgot to mention, you can certainly download 24 bit files @ 44.1, 48, 88.2, 96, 176.4 and 192
I have all bit and sample rates downloaded in Wav or Flac. Your DAC will need to be compatiple to play, some DACs won't play above 96K.

First, I would recommend that you use dbpoweramp to convert one of your FLAC files to .wav and then compare these.

Then, in the long-run get a Mac Mini and leave the PC behind. Much better SQ IME.

Your PC can output 24/192 with the right USB interface. This usually requires a special driver.

Steve N.
Empirical Audio