Beware of the installer.
A typical linux install will ask which partition to install on, and even allow resizing and such using programs like gparted. This is because the typical linux user multi boots to windows and other linux distro's.
On a media computer, it is smart to have a linux partition and a data partition, so that the OS can be reinstalled without deleting the data.
This is the only 'major' linux distribution I've ever seen that does not even bother to warn the user before wiping hard drives.
I've installed lots of linux distro's, this is the worst.
After telling the installer which drive to install on, I fully expected it to ask which partition. It didn't. Lame.
First off this is not a 'Linux distribution' as such.
Secondly both on the Wiki and here in the Forum we make it clear that the DVD installer will wipe the drive you point it to install too - http://wiki.linuxmce.org/index.php/Mirrors_0710
. If you need to do a non-destructive install then there is the CD installer.
I'm sorry that you lost data but you need to read the installation notes more carefully.
All the best