My family's first computer had Windows 3.1 on it. Except for Paintbrush, it was pretty useless for the most part, but all the cool shit at the time was on DOS anyway, so it didn't matter.
But yeah, that "Ta da!" sound really brings me back.
My 25 mhz Olivetti PCS 33 would often hand doing the 3.1 startup noise, leaving the computer going DUN DUN DUN DUN DUN DUN DUN DUN DUNDUNDUNDUDUDUDUDUDUDUDDDDDDDDDDDUUUUUUUUUUUUUUUUUU until I turned it off.