Ubuntu will not boot up since updated to 9.10 on 29 Oct 2009

Yes it will delete all of your files. But here's what I suggest: assuming you can indeed get Ubuntu started, copy all of your Documents, Music, Pictures, etc., to an external hard drive (a 320 GB one should cost no more than $70.00 if you need to buy one).

Then completely reinstall Ubuntu from your disc. After Ubuntu is installed and configured to your liking, you can copy back your files from the external drive to your computer.

I have had to do this several times (including two days ago) since I started using Ubuntu about a year and a half ago. It's time-consuming (takes an afternoon) but is quite easy to do.

I routinely back up all of my files at least once a week and more often (as much as two times in a single day!) if I have added something important, such as pictures or music. I recommend that everyone do that too. Thus, if and when you have to reinstall your operating system (whether it be Ubuntu, another Linux system, Mac, or Windows), you won't lose anything of importance to you.

I hope this is of some use to you.

Thank you Lawrence, thats what I thought.