How do I remove my old ubuntu installation and install a new install without affecting my Windows 8 install

Question

I have downloaded Ubuntu 12.04 64 bit for my laptop, as I installed 13.04 and I have quite a few bugs and errors. Since 12.04 is the most stable version and it's also LTS, I will stay with that one.

I have a few questions though, since I'm still new to Ubuntu. How can I install 12.04 and delete my 13.04 installation, without touching AT ALL my Windows 8 installation, as I am running dual boot, and installed 13.04 alongside Windows 8.

Solution

If you boot the live CD of 12.04 and then start the install. It will scan your disks and then should find 13.04 and then ask you if you want to "Replace 13.04" or do "Something Else".

Selecting to replace 13.04 will only affect the partition with Ubuntu already installed but..... IT WILL ERASE ALL FILES IN THE UBUNTU INSTALL!!! If you want to keep any of these files you will need to back them up to another location BEFORE installing 12.04.

If you have installed 13.04 as encrypted, I'm not sure that it will be found. If that is the case you will(likely) need to delete the 13.04 partition manually and then try to install 12.04 from scratch with the liveCD installer.
The easiest way to do that is with OS-uninstaller This will need to be done with the liveCD/USB, if needed the community wiki page is here... I will refer you to that page rather than just give you the instructions, the ones there are excellent and include screenshots as well.

Just remember using either method will delete all the files on the Ubuntu partition so back them up first if you want to save them. Neither will affect your Windows partition.

NOTE: if you are confused by the screen or you do not get the option to replace Ubuntu 13.04 with 12.04 Please do not do anything, just press cancel and then seek further help while the installer is pretty safe there are sometimes errors that usually come down to the operator not paying attention or being in a hurry and pressing buttons without reading them.

Comments

[TrailRider]

@Githlar I'm not sure but I believe you are right, I don't use encryption so I could say for sure. I only mentioned that as a potential problem. Regardless, wouldn't /home still be unreadable to the new install since the encryption is down at the time of the install? I guess the best answer I can give to that is that if you used encryption or are not sure don't follow my instructions, as you may end up with a OS with no usable /home Thank you for pointing that out and helping to avoid my instructions causing confusion/errors.

[Chuck R]

There is a way to mount the encrypted home from /home/[username] -- though, frankly, I've never been able to get it to work for some reason. It may require a module that's not loaded in recovery mode (the only place I've tried it) in order to mount it. There's a "Access my files.desktop" (or something similar) and .sh file if I remember correctly that you should be able to use to again access to the encrypted home in order to recover files. The only caveat is that you have to have saved the private key from ecryptfs-unwrap-passphrase in order to do so.