How do I reinstall LL safely in a win7/zorin/lubuntu/LL multiboot?

[gold_finger]

Is the only reason you're re-installing LL 2.8 because you added that to the setup first, then added Lubuntu and now can't boot into LL 2.8 because grub menu item for it does not work?

If so, all you need to do is use live LL 2.8 dvd/usb to re-install grub from LL on disk to the MBR of the drive putting LL back in control of booting.  To do that follow these steps.  (NOTE:  I'm putting all instructions within code blocks -- just because I'm lazy.  Every line that begins with a "#" is just a comment line describing the command that follows it.  Only enter the commands into your terminal, not the comment lines.  Also, I'm assuming that you are not using a separate /boot partition on the drive.)

Code:

# Use the blkid command to list your partitions.  Make note of the LL 2.8 root partition device name.
sudo blkid -c /dev/null

# In examples below, X is the drive letter (a, b, c, etc.); Y is the partition number (1, 2, 3, etc.).
# Mount your LL 2.8 root partition to /mnt
sudo mount /dev/sdXY /mnt

# Run following command to install grub.
sudo grub-install --boot-directory=/mnt/boot /dev/sdX

# Unmount your LL 2.8 root partition.
sudo umount /dev/sdXY

# Close terminal and reboot computer.

# If all OS's don't show up in menu on reboot, boot into system then run this command to add them to menu:
sudo update-grub

# Done.

If fixing grub booting was not the problem and you really do need to re-install, you do not need to use GParted to delete the current LL partition first.  Just boot your live LL 2.8 dvd/usb, start the installer, pick the "Something else" install option.  That will bring you to the partition selection page where you can designate which partition to use for the install.  Just highlight the current LL root partition, click "Change" button.  In pop-up box:

• Use as = Ext4 file system
  
• Size = leave as is
  
• Mount Point = /
  
• Format = check box to format
  
• Click "Done".  (If you get a message complaining that you changed the size of the partition -- even though you did not -- ignore it and click "Go Back" button.  All will be fine.)
  

No need to do anything with Swap partition -- it will get used automatically.


Near bottom of window, "Device for boot loader installation" should be set to "/dev/sda", assuming the drive being booted from is sda.


Click "Finish" button to complete the installation.  It will now re-format the old LL root partition and re-install to same place.  LL's grub will be in charge of booting all of the OSes, which is what you want.  (Having any other distro's grub in charge will result in failure to boot LL.)


If computer boots straight into LL without showing grub menu with other OS choices, open a terminal in LL and enter this command:

Code:

sudo update-grub

On next reboot all choices should show-up.


P.s.  If you're not sure which partition the current install of LL is on, just boot into it then enter this command in a terminal:

Code:

lsblk

Look to see which partition has the "/" (root) mount point listed next to it -- that's the partition you want to re-install to.