I am updating this post in October 2009 to include my desktop wallpaper image. This has nothing whatsoever to do with Monty Python, but it ties in with the theme of customisation. Originally, this post contained only the information on sound effects.
The sound effects allocated for system events on my Windows XP computer are Monty Python quotations, sourced from the .wav files included in Monty Python’s Complete Waste of Time. Here are a few examples.
Start Windows. “Are you nervous?” (Spoken by John Cleese on a quizshow sketch from How To Irritate People.)
Exit Windows. “That was really horrible! / Oh, you’re always complaining.” (Spoken by Idle/Jones in Episode 29.)
System notification. “We interrupt this program to annoy you and make things generally irritating.” (Spoken by Eric Idle in Episode 30.)
Empty recycle bin. “Well, that’s quite enough of that!” (Spoken by Terry Jones in Episode 13.)
Below is a copy of the image I use as my desktop wallpaper.
It’s a fractal image that to me has always hinted at a metaphorical, artistic meaning, suggested by the title Mandelbrot Ex Machina. It has it all – regions with mechanic regularity, regions with moire patterns, regions with fractal self-similarity, and regions with complete disorder. In the centre is what looks to me like a cogwheel with mandelbrot shapes instead of cogs, part of a machine that endlessly grinds away turning order into the sawdust of chaos. Beyond that, the meaning is entirely open to interpretation.

1 Nov 2009 at 6:51 am
I never quite understand how people can cope with finding things on such visually noisy desktops. My desktops were always plain subdued colors until the coming of Ubuntu Hardy, where I kept the heron image.
Maybe it’s all about muscle memory.
1 Nov 2009 at 9:32 am
Well, in my case the desktop image doesn’t fill the whole screen; it’s centred, with a thick black border around it, and all the desktop icons fit within the border.