Hi all. I seem to need help.

Overnight, my ubuntu installation appears to have developed a major problem. It fails to boot.

To be more exact, the computer starts normally when switched on, but it takes ages for the GRUB screen to appear. Once I choose for it to boot in Ubuntu, it switches to a purple screen (no loading indicator, just purple), or occasionally to a black screen with a flashing cursor. After that, nothing happens.

I have tried to boot through recovery mode, but that does not work either.

This problem occurred suddenly, literally overnight. I think the evening before, ubuntu performed some updates. I run on a dual install with Windows 7, which I hardly ever use (I do right now, of course).

Can anyone suggest what I might do about this?