[SOLVED] Unwanted Wake from Sleep on Vista

By Fungi008:

Vista's dumb multimedia sharing option: More complex (and I don't think anyone else has posted it). Do this:
Control Panel -> Power Options -> If "High Performance" is selected, choose something else, like "Balanced" (I don't know why this works) -> Change plan settings (for the chosen power plan) -> Change advanced power settings -> Scroll down to Multimedia settings -> Choose "Allow the computer to sleep"

Thanks, Fungi008!