The other day one of my friends called me with a puzzling problem: her MacBook would start up, she could log in, and…that was about it. Running any programs resulted in a quick quit, including the Finder. The repair person she was talking to said that if it was a hardware problem, it’d be covered and they could do it for free…but software she’d have to pay. And they said it was software. She decided that it’d be easier to just do an Archive & Install and start fresh than pay them, which was a good decision IMO. (She’s not particularly tech-savvy, but she could certainly do a reinstall and get things working.) But she asked me to look at it first.
She logged in, and I saw what she meant. Finder would start up and show its menus across the top, but as soon as I opened a window it would crash. System Preferences showed its usual array of preference panes, but trying to open one caused a crash.