The Windows 95 sound (which I rather like) was done by Brian Eno, a noted ambient composer. From an interview Eno gave (found on his Wikipedia page):
"The idea came up at the time when I was completely bereft of ideas. I'd been working on my own music for a while and was quite lost, actually. And I really appreciated someone coming along and saying, "Here's a specific problem X solve it." The thing from the agency said, "We want a piece of music that is inspiring, universal, blah-blah, da-da-da, optimistic, futuristic, sentimental, emotional," this whole list of adjectives, and then at the bottom it said "and it must be 3 3/4 seconds long." I thought this was so funny and an amazing thought to actually try to make a little piece of music. It's like making a tiny little jewel. In fact, I made 84 pieces. I got completely into this world of tiny, tiny little pieces of music. I was so sensitive to microseconds at the end of this that it really broke a logjam in my own work. Then when I'd finished that and I went back to working with pieces that were like three minutes long, it seemed like oceans of time."
ah, fond memories of programs crashing, and then eventually being thankful they were only crashing if i used bad device drivers (but if you did, the entire OS would go down), and then rarely crashing at all.
"The idea came up at the time when I was completely bereft of ideas. I'd been working on my own music for a while and was quite lost, actually. And I really appreciated someone coming along and saying, "Here's a specific problem X solve it." The thing from the agency said, "We want a piece of music that is inspiring, universal, blah-blah, da-da-da, optimistic, futuristic, sentimental, emotional," this whole list of adjectives, and then at the bottom it said "and it must be 3 3/4 seconds long." I thought this was so funny and an amazing thought to actually try to make a little piece of music. It's like making a tiny little jewel. In fact, I made 84 pieces. I got completely into this world of tiny, tiny little pieces of music. I was so sensitive to microseconds at the end of this that it really broke a logjam in my own work. Then when I'd finished that and I went back to working with pieces that were like three minutes long, it seemed like oceans of time."