How can I force Ubuntu 9.10 to reinstall itself without losing my information?

"To reinstall without losing your info ...

Make a backup of the info you want to keep.
Test the backup.
Reinstall. Make sure the root partition gets reformatted, because you want to get rid of the old Ubuntu 9.04 stuff completely.
Restore the backup.

You could attempt to perform the installation and try forcing the installer not to format the root partition, and that would keep the files you're probably interested in keeping. But it would leave files around from the previous install, it might lead to problems during the installation, and it might create problems later.

I don't know what you're considering ""your information"", but I'm assuming your user's HOME directory (or the entirety of /home) is the main candidate. If you have a website or database installed you'll also want to back those up (usually these are under /var).

And you probably want to make a backup of /etc as well, but don't automatically restore that one.

To reinstall without an install disc ...

Ubuntu provides many installation options; installing from the CD is only one of them. See the Installation page at the Community Ubuntu Documentation.

In particular, here is the section on Installation without a CD:

The documents listed below provide instructions for installing Ubuntu
without using a CD or CD-ROM drive.


SmartBootManager - Installing from a PC which will not boot from a CD.
Installation/FromUSBStick - Installing from a USB memory stick.
Installation/FromCForUSBStick - Similar to above but using grub.
Installation/WithFloppies - Installing without a CD drive over a network.
Installation/FromHardDriveWithFloppies - Installing without a CD drive or network capabilities from a hard drive.
Installation/FromWindows - Installing from Windows without using floppies, a CD, or any other removable media.
Installation/FromLinux - Installing using a spare partition from an existing Linux system to house the Ubuntu CD image.
Installation/FromVM - Installing using a physical disk to a Virtual Machine.
See also the network installation options below


As you can see, there are lots of options. I think the best option might be to use a USB stick (Installation/FromUSBStick), if that's an option for you. If you still have the LiveCD ISO, or can download it again, and you have a spare USB stick you can use, this is a good option.

Installing from within a running Linux (Installation/FromLinux) might be an option for you, but it can be complicated -- in particular the debootstrap option (bottom of the page) is very powerful, but the process is not for the faint of heart.

Finally, one of the network installation options might work."

"First you have to explain what the ""issues"" are. Are they system wide or local to your user account?

The first thing you could do is add a new user. Login with that user and see if the issues go away. If they do, the easiest thing to do would be to just move your documents/media to the new user account.

If the problems don't go away, then that is easy to fix as well.

What I would do is purge all non-standard software to get down to a bare bones install. this means removing all of X, gnome, etc.

#this will list all non crucial packages
aptitude search '~i (~poptional|~pextra)'
#this should remove them all.
aptitude purge '~i (~poptional|~pextra)'

aptitude might flip out about removing that many packages at once so it might be easy to do them in chunks..

aptitude search '~i (~poptional|~pextra)' -F %p|xargs -n 20 echo aptitude purge > /tmp/cleanup.sh
sh /tmp/cleanup.sh

once everything is removed, do a

aptitude reinstall '~pstandard'
aptitude install ubuntu-desktop

that should get you a almost-like-new system.

Most of that is probably irrelevant though, since adding a new user account with fresh settings will probably fix any issues you are having."