No sound on Windows XP

Hello, I just downloaded Muse Score on my WinXP and I get no sound. I tried several options in the I/O settings, but no results whatsoever. I have some Realtek onboard soundcard (I am not sure, but probably Realtek ALC662), and my current settings on Muse Score are (not sure in English, translating from Spanish):

Use JACK MIDI output (unchecked)
Use internal synthesizer (checked)
Jack audio server (unchecked)
ALSA audio (unchecked, disabled)
Portaudio (checked)
API: MME (other options available: MME, Windows Direct Sound, ASIO, skeleton implementation)
Device: Microsoft sound assigner - Output (other options available: Microsoft sound assigner - Input, Realtek HD audio input, Realtek HD audio output)

Select input interface for PortMidi (an empty combo box)

The soundcard is working for other applications, including Encore and VLC, though VLC is not reproducing MIDI because it says a soundfount should be configured and I could not figure out where to do it.