I tracked down the source for anyone curious.Don't feel like clearing work-related stuff off my screen, so here's just my wallpaper:
I think this is the only wallpaper I've had on this laptop since I got it a few years ago. Also replaced my system sounds with pony clips. When I empty the recycle bin, RD says, "Time to take out the adorable trash," and naturally the error sound is, "I just don't know what went wrong." I set it to play, "Can't hear ya, I'm asleep," when it shuts down, but that one never actually plays for some reason.
I found a sound board with downloadable mp3s on deviant art. I imagine it varies depending on your version of Windows (or whichever OS), but the menu for customizing your system sounds should be in the same area as the menu for changing your wallpaper and such.I wouldn't mind changing my default windows sound stuff to poni. Do you just need to get to the right folders and have the right format audio?
The links there are dead, namely the link to the new version that also has the .mp3 files. But yeah, I can see how I'd change the sounds. No problemo from what I can tell.
Oh hey! Desktop ponies! Been awhile.