Cakewalk Analytics can query what's being assigned to SONAR's outputs. A surprisingly (some would say disturbingly

) large number of SONARians use ASIO4ALL. I know that ASIO4ALL can work with some systems and it's quite ingenious, but I think even the designers would say it's a kludge. Frankly, if ASIO4ALL disappeared from the face of the earth, I think it would eliminate a lot of need for support for Windows DAW and interface manufacturers, and quite a few forum threads about software "not working."
If someone's committed to using ASIO4ALL, then use it for a laptop (if you have a desktop, you should have a proper ASIO interface), and make sure no other audio drivers are installed. That's the only way I've gotten it to work.