Hopefully this has not been treated elsewhere. I've already searched for help.

My installation stopped detecting any hardware earlier today. I'm really not sure what could have happened, because I did not install anything or change my configuration. I did accidentally run the Update Manager without being connected to the Internet, but I doubt that would have done anything.

1) my sound card stops working (a mute sign displayed through the icon)
2) random graphic corruption (my ATI x1600, which was previously working, now runs slowly and garbles some buttons (eg. the "hide windows" button))
3) my network connection no longer functions (it claims that no hardware is detected)
4) my trackpad (!) stopped working

I noticed just before this nonsense started that a USB mouse failed to operate on being plugged in. Funnily, it is now the only pointing device that works.

Everything functions as normal when running off of the Live CD.

Many thanks in advance to anyone who has the time to help.