The is actually a file named gm.dls , typically located in the C:\Windows\System32\drivers folder.
If you were a kid in the late 90s or early 2000s, you know exactly what I’m talking about. You boot up your family’s beige Compaq or Gateway tower. The Windows 98 splash screen fades. You open a MIDI file you just downloaded from a fan site for your favorite video game. windows default soundfont
The soundfont follows the standard, ensuring that any MIDI file played through it will use the correct instruments (e.g., Program 1 is always Acoustic Grand Piano). The is actually a file named gm