A few months ago I purchased a Gazelle Professional laptop. I've been very happy with it.

Recently I executed an errant dpkg command that ran roughshod over my system, deleting numerous critical system files. I was left with no choice but to reinstall Ubuntu from DVD. The process was unexpectedly painless, even preserving my home directory, but I'm left with a system that's broken in some important ways:

1. The touchpad is nonresponsive, and remains so even after I press FN+F1.
2. There's no sound.
3. When I open the hibernating laptop, the screen flashes briefly, but then remains dark. I have to power-cycle it and log back in to get back to the desktop.
4. After a minute or so of use, a dialog appears, presenting an important-looking but vague warning: "System program problem detected / Do you want to report the problem now?"

Tips for how to remedy any or all of these issues would be greatly appreciated.