Default Soundfont Better: Windows
If you search online, you might find a file named gm.dls (approx 3.9 MB). This is the closest you will get to the raw, editable default sound set.
This partnership is why the file is named and contains a "Copyright Roland Corporation" string. This created a universal standard; a MIDI file played on a Windows 98 PC would sound nearly identical to one played on a Windows 10 machine, preserving the composer's intent across decades. windows default soundfont