Per the title, Skype won't open, throws an APPCRASH error code #C0000005.
I have already tried:
Checking the "compatibility" setting
Removing the appdata/roaming/skype folder (it doesn't exist anyway)
Installing versions 5.3.113, 5.3.116, 5.3.120
Checking audio and video drivers for most recent updates
Uninstalling with "advanced" registry checking using Revo Uninstaller
Anyone got some gems of experience to throw my way?
(Unfortunately, it's someone else's computer, and they don't know the last thing they did before it stopped working...)