Start -> Run and type, "dxdiag.exe" without the quotes and hit Enter.

You can use the "Next" button to test all DX functions or just go to the "Music" tab at top to see all microsoft synths and test them.

The two sound identical, but you may be being fooled by the one being louder. They are both poor choices for music makers these days, I suggest you try the Coyote synth that ships with BiaB, or some other DXi or VSTi MIDI synth solution anyway. Neither microsoft synth option was designed with real music making in mind, cheezy sounding stuff.
Even using one of the VSTi's that allow loading of Soundfonts can easily blow that thing out of the water.


--Mac