1. Edirol does not have drivers for the UA-1A for Win8.1 like they do newer devices.
2. What is the M-Audio USB audio box; what is the model number?
3. PT Pro Audio told you that there was a MAC driver instead of a Win driver for the M-Audio device?
4. Can you get any output from the M-Audio device; like with a good old music file on the Win 8.1 computer?