Ha! The New Jersey Transit ticket kiosks at 8th street station in Philly make the same Windows ding noise. It sounds like a program is stuck on an error, and it's like a dog whistle to me.
That said, about your comment "Someone who does sound design could pick up this banner and impress everyone with set of free UI sounds that are classic and usable." -- I'm betting that's exactly what MS was trying to do. They commissioned Brian Eno to do the Windows 95 startup sound, and brought on Robert Fripp for Vista's startup sound (along with Tucker Martine and Steve Ball). Mind you, I'm not sure who's responsible for the various system sounds.
It's very easy to say "make classic, usable, impressive UI sounds" but incredibly difficult to actually do that.
Not only is it annoying but it broadcasts "You are using a Windows machine". Which to be also broadcasts "This machine is completely untrustworthy for financial purposes."
I hear those weirdly-out-of-place Windows sounds everywhere. It grates on me the same way Comic Sans grates on those who appreciate type.
Someone who does sound design could pick up this banner and impress everyone with set of free UI sounds that are classic and usable.