Why "remove Ubuntu 12.04 and replace it with Ubuntu 13.10" means to use all of the disk and lose all data?

Question

I recently decided to move to Ubuntu 13.10 (by move I mean install from ISO not update)

My Ubuntu 12.04 had 3 partitions

• SWAP partition
• LINUX partition (ext4)
• NTFS partition OF 500GB of DATA

Why selecting the option "remove Ubuntu 12 and replace it with Ubuntu 13" decided to mess with my partition scheme ? Why did it decided to REMOVE THE NTFS and make me lose YEARS and YEARS of data by using all disk and not reuse the SWAP and EXT4 partition of the version 12.04?

Also a BUG has been open https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1265192

ADDED:

I first tried TestDisk but the one that helped me was PhotoRec I recovered as many files as posible from the lost partition

VERY IMPORTANT

As soon as a picture or file is accidentally deleted, or you discover any missing, do NOT save any more pictures or files to that memory device or hard disk drive; otherwise you may overwrite your lost data. This means that while using PhotoRec, you must not choose to write the recovered files to the same partition they were stored on.

This also applies for any other tool not just for the two that I have mentioned

For further info about this tools take a look at this

How to resolve " The harddisk seems too small" with Testdisk deeper search option

Answer 1

To reuse the ext4 and SWAP partition you need to specify them manually using the advance install (select the "something else" option).

_{(source: linuxbsdos.com)}

Now you just need to unmark the ntfs partiton and mark down the partitions you will be formating for the install (you don't need to format the SWAP partition).

Please note that unless you have a separate home partition, formating will also delete the files you had on the ext4 partition. Consider moving your home to it's own partiton or create a separate home partition while installing Ubuntu.